Chicago Author-Date Style

Block quotation

  • Text including block quotations, notes, bibliography entries, table titles, and figure captions must be double-spaced. 
  • For block quotations five or more lines, or >100 words, should be blocked. 
  • Blocked quotation does not get enclosed in quotation marks.  
  • Use a 1/2″ indent for paragraph beginnings for block quotes and hanging (bibliography) indents.

Fuchs (2014) believes:

Neither techno-optimism nor techno-pessimism is the appropriate method
for analyzing social media. Rather, one needs to decentre the analysis
from technology and focus on the interaction of the power structures of
the political economy of capitalism with social media (p. 256).

An extra line space should immediately precede and follow a blocked quotation.


  • Number the pages in the top right corner of the paper, beginning with the first page of text.

2.8Line spacing

Though authors may prefer to use minimal line spacing on the screen, publishers have customarily required that any printout be double-spacedincluding all extracts, notes, bibliography, and other material.

except for block quotes that are single spaced(in 16th ed). (in 17 this exception is removed)


Author-Date Style In-text Citation: Parenthetical References (p. 620-624)
In parentheses, cite the author’s last name, followed directly by the publication year with no punctuation

Where the author’s name is mentioned in the sentence, cite the publication date in parentheses after the author’s last name wherever it appears in the sentence and before a mark of punctuation.

To cite a particular part of a source, include the last name and publication year, a comma, and page number(s);

for journals, include the last name and publication year, a comma, the volume number, a colon, and page number(s).

A citation for a journal article appearing in the text as either:

Cite at the end:

Start of a paragraph … blah blah …….blah blah …….blah blah …….blah blah ……………..    …………………  (LN and LN Year, page).

Blah …………………………………………………  blah. The following passage will be blah ……………………………. blah enlightening:

blah ….. blah I….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah . (Crump 2006, 53)

An extra line space should immediately precede and follow a blocked quotation.



LN (1984c) confirms that blah blah ………………… ………………. …………….. …………………… ……. measured (page).

As FN LN points out, “blah blah blah blah blah  blah blah blah blah blah blah blah blah” (year, page).

Cite at the beginning:

LN, LN, and LN (1998, 243) argue that Blah   ….. blah   ………. blah blah blah blah blah blah blah blah blah blah blah.

Wider blah blah……………… , LN (year, page) claims:

Iblah ….. blah I….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah ….. blah .


Chicago Author-Date:

Lastname, Firstname. Year.  Book in italics. City: publisher.

Lastname, Firstname. Year.  Book in italics.  City, StateOrCountryAbbr: publisher.

Lastname, Firstname. Year. “article title in double quote.” Journal of Publication in italics. City: publisher.

In the reference list, do not abbreviate “edited by” or “translated by”.

Lastname, Firstname. Year. “article title.” In EditedBook in italics, edited by FN LN, page-page. City: publisher.

Lastname, Firstname, FN LN, and FN LN. Year. “article title.” In EditedBook in etalics, edited by FN LN, page-page. City: publisher.

no comma after Journal before volume

Lastname, Firstname. Year. “article title.”  Journal in italics Volume (issue): page-page. City: publisher.


The author-date system has long been used by those in the physical, natural, and social sciences.

Citing sources in this style consists of two parts:

  1. An in-text citation
  2. A reference list

In this system, sources are briefly cited in the text, usually in parentheses, by author’s last name and date of publication. From this point of view it is similar to APA.

The short citations are amplified in a list of references, where full bibliographic information is provided.


Footnotes or end-notes can be used to supplement the Author-Date style to provide additional relevant commentary and/or to cite sources that do not readily lend themselves to the Author-Date References system.


Numbered Headings/Subheadings   (17th edition 2.18, 8.159 and 8.160)

Each subhead on a new line, flush left. Each level of subhead must be clearly distinguished so that the different levels can be identified and carried over for publication.

Numbering of sections, and subsections provides easy reference. Sections are numbered within chapters, subsections within sections, and sub-subsections within subsections. The number of each division is preceded by the numbers of all higher divisions, and all division numbers are separated by periods, colons, or hyphens. For example:

12.2-24: Numbering displayed mathematical expressions

Chicago prefers headline-style capitalization for subheads, with no period added at the end.

*Capitalize the first and last words in titles and subtitles. Capitalize all other major words. But Lowercase words to and as, articles the, a, and an as well as common coordinating conjunctions and, but, for, or, and nor.

4.5 Democracy That Works Is Better Than Dictatorship That Do Not

*An exception is made for run-in heads, italicized and followed by a period and capitalized sentence-style:

*Lowercase prepositions, regardless of length (except when they are used adverbially or adjectivally (up in Look Up, down in Turn Down, on in The On Button, to in Come To, etc.) or when they compose part of a Latin expression used adjectivally or adverbially (De Facto, In Vitro, etc.))

4.6 Three Hypothesis concerning the Democracy according to Plato

*Lowercase the part of a proper name that would be lowercased in text, such as de or von.

4.7 Accusers of Comte de Monte-Cristo Fail the Job

*Lowercase the second part of a species name, such as fulvescens in Acipenser fulvescens, even if it is the last word in a title or subtitle.

4.8 From Homo erectus to Homo sapiens: A Brief History


The first sentence of text following a subhead should not refer to the subhead; words should be repeated where necessary. For example:


Chicago Headings Type 2




4. Centered, Boldface or Italic Type, Headline-style Capitalization 


4.1 Centered, Regular Type, Headline-style Capitalization


4.1.1 Flush Left, Boldface or Italic Type, Headline-style Capitalization  

4 Flush left, roman type, sentence-style capitalization


Run in at beginning of paragraph (no blank line after), boldface or italic type, sentence-style capitalization, terminal period.

Democracy in media. It is blah ………..




Figures should be placed as close as possible to the text to which they refer.

Label all drawings, photos, charts, graphs, maps, etc. as “Figure” or “Fig”

below the image, followed by an Arabic numeral, a period, and a caption.

Number tables and figures separately in the order you mention them in the text. 
In the text, identify tables and figures by number (“in figure 3”) rather than by location (“below”).

For example:

Figure 1. Gandhi the same font and size of the text



In text Citation examples for Author-date Chicago system (best)

Murdoch University Site:

Use only the surname of the author followed by the year of publication. Include page, chapter, section or paragraph numbers if you need to be specific.

A comma is placed between the year of publication and the page, chapter, section or paragraph numbers.

No distinction is made between books, journal articles, internet documents or other formats except for electronic documents that do not provide page numbers. In this instance, use the paragraph number, if available, with the abbreviation par.

Citations in the text can either be either placed at the end of a sentence in parentheses (brackets)


alternatively, the author’s name may be included in the text, and just the date and additional information placed within the brackets.


A citation for a book appearing in the text as:

There are many reasons for intestinal scarring (Ogilvie 1998, 26-28).

in the reference list:

the publication name is italic

The title of a chapter in book or title of an article in a publication is in double quote not italic:

Ogilvie, Timothy H. 1998. Large Animal Internal Medicine. Baltimore, MD: Williams and Wilkins.


I n citations o f a chapter o r similar part o f an edited book, include the
chapter author; the chapter title, in quotation marks; and the editor.

Precede the title of the book with In. Note the location of the page range for
the chapter in the reference list entry.

LN, FN. Year. “aaaaaa.” In edited book , edited by Amir Ghaseminejad, page-page. city:publisher

Gould, Glenn. 1984. “Streisand as Schwarzkopf.” In The Glenn Gould Reader, edited by Tim Page, 308-11. New York: Vintage.




A citation for a journal article appearing in the text as either:

Cite at the end:

… gastrointestinal illness is also often misdiagnosed (Morgan and Thompson 1998, 243).


Foucault (1984c) confirms that “criticism and philosophy took note of the disappearance” (103).

Cite at the beginning:

Morgan and Thompson (1998, 243) argue that gastrointestinal illness is also often misdiagnosed.


In reference lists, no page numbers are given for books;

For journal articles or chapters or other sections of a book, the beginning and ending page numbers of the entire article or chapter are given.
referenced as:


Morgan, U. M., and R.C. A. Thompson. 1998. “PCR Detection of Cryptosporidium: The Way Forward.” Parasitology Today 14 (6): 241-245.

Blair, Walter. 1977. “Americanized Comic Braggars.” Critical Inquiry 4 (2): 331-49.
( B l a i r l ’77, 331 32)

no comma between the journal name and volume (issue):page-page.

Karmaus, Wilfried, and John F Riebow. 2004. “Storage of Plastic and
Glass Containers.”
Environmental Health Perspectives 112 (May) : 643-47. http://www


The DOl is preferred to a URL
Note that DOl, so capitalized when mentioned in running text, is lowercased and followed by a colon (with no space afer) in source citations.

Novak, William J. 2008. ‘The Myth ofthe ‘Weak’ American State. ” American Historical Review 113:752-72. doi:l0.1086/ahr.ll3.3.752.


An electronic document would be cited in the text in the same way as a print document.
For example, citation for an internet document appearing in the text as:

There are many useful materials available (Raidal and Dunsmore 1996,  par. 13)

would be given in the reference list as:

Raidal, Shane R., and Jon Dunsmore. 1996. Parasites of Companion Birds: A Survey of Alimentary Tract Parasites.


Note: When referring to multiple authors within the text and within parentheses, precede the final name with the word and

… as Kurtines and Szapocnik (2003) demonstrated.
… as has been demonstrated (Kurtines and Szapocnik 2003).


Purdue OWL: Chicago Manual of Style 16th Edition


This guide outlines the author-date system.

In text Citations examples

In text Citation examples for Author-date System


There are four common methods of referring to a source document in the text of an essay, thesis or assignment. These methods are direct quotation from another source, paraphasing or summarising material, and citing the whole of a source document. In academic writing, most of your essay or assignment should be phrased in your own words and the overuse of direct quotation should be avoided.


Short quotes

  • Quotations match a small section of the source document word for word and must be attributed to the original author and enclosed within quotation marks. When quoting, the relevant page number(s) must be given:

    Larsen (1991, 245) stated that “many of the facts in this case are incorrect”.

  • If information is left out, three dots … must be used to show where the missing information goes:

    As Ballard and Clanchy (1988, 14) have argued, “Learning within the university is a process of gradual socialization into a distinctive culture of knowledge, and … literacy must be seen in terms of the functions to which language is put in that culture”.

Longer quotes (block quotation)

    • In general, avoid using too many long quotes and remember to introduce or integrate quotations smoothly into the rest of your assignment
    • You may choose to indent a larger block of quoted text. Such blocks of quoted texts usually consist of more than one sentence or more than 40 words
    • Blocks of quoted text should be indented from the left margin only, single spaced and may be one point smaller than the standard font size:


Wider applications are increasingly being found for many drugs such as invermectin. For example, Crump (2006, 53) confirms that:

Ivermectin – already used extensively in animal health and in eliminating onchocerciasis and lymphatic filariasis, two of the most disfiguring and deleterious human diseases – is now being used commercially for the treatment of strongyloidiasis, mites and scabies.


Wider applications are increasingly being found for many drugs such as Aspirin. The following passage will be enlightening:

Ivermectin – already used extensively in animal health and in eliminating onchocerciasis and lymphatic filariasis, two of the most disfiguring and deleterious human diseases – is now being used commercially for the treatment of strongyloidiasis, mites and scabies. (Crump 2006, 53)

Quotations within quotations

  • Use a single quotation mark to indicate previously quoted material within your quotationShort Quotation:

    She stated, “The ‘placebo effect’ … disappeared when behaviors were studied in this manner” (Miele 1993, 276), but she did not clarify which behaviors were studied.



    Miele (1993) found that “‘the placebo effect’, which had been verified in previous studies, disappeared when behaviors were studied in this manner” (276).


The author-date system inserts minimal source information directly into the text itself, surrounded by parentheses, and follows up with the rest of the source information in a list of references at the end of the paper. Imagine that you’re writing a paper on the ideal politician and are quoting a particular author’s ideas about desirable qualities in a politician. An excerpt from a sentence in the text of a paper written using the author-date would look like this:

While some assert that the essential qualities a politician must possess
are, "passion, a feeling of responsibility, and a sense of proportion"
(Weber 1946, 33), others think that ...

The entry in the list of references would look like this:

Weber, Max. 1946. Politics as a Vocation. In  Essays in Sociology, edited by
     H.H. Garth and C. W. Mills, 26-45. New York: Macmillian.





Author-date: “References”

letter-by-letter alphabetical order according to the first word in each entry.

Sources you consulted but did not directly cite may or may not be included.

the date is immediately after the author’s name.


entries are singled-spaced

Two blank lines should be left between “References” and your first entry.

One blank line should be left between remaining entries


Citations beginning with names and those beginning with titles are to be alphabetized together. Numbers in titles are treated as though they have been spelled out. For names, alphabetize based on the letters that come before the comma separating the last name from the first, and disregard any spaces or other punctuation in the last name. For titles, ignore articles such as “a” and “the” (and equivalents in other languages) for alphabetization purposes.


Blair, Walter. 1977. “Americanized Comic Braggars.” Critical Inquiry 4 (2): 331-49.
Becker, Elizabeth. 2003. “U.S threatens to act against Europeans over modified foods.”New York Times, Jan. 10.
Brest, Martin. 2003. Gigli. DVD. New York: Sony Home Entertainment.
Couper, Heather, and Nigel Henbest. 2002. “The hunt for Planet X.” New Scientist, 14 December, 30-34.
Delaroche, Paul. 1829. “Portrait of a Woman,” pastel drawing (Ackland Art Museum, Chapel Hill, NC). In European Drawings from the Collection of the Ackland Art Museum, by Carol C. Gillham and Carolyn H. Wood. Chapel Hill: The Museum, University of North Carolina, 2001, page 93.
Fildes, Alan, and Joann Fletcher. 2001. Alexander the Great: Son of the gods. London: Duncan Baird.
Freud, Sigmund. 1950. Beyond the pleasure principle. Translated by James Strachey. New York: Liveright.
Gezon, Lisa L. 2002. “Marriage, kin, and compensation: A socio-political ecology of gender in Ankarana, Madagascar.” Anthropological Quarterly 75 (4): 675-706.
Google. 2009. “Google Privacy Policy.”
Haas, Stephanie. 2007. “Relational algebra 1.” (lecture in Introduction to Database Concepts and Applications, University of North Carolina, Chapel Hill, NC).
Haldon, John. 2002. “Humour and the everyday in Byzantium.” In Humour, history, and politics in late antiquity and the early Middle Ages, edited by Guy Halsall, 48-71. New York: Cambridge University Press.
Hedges, Chris. 2000. “When armies of conquest marched in, so did saints.” New York Times, February 12, LexisNexis Academic.
Kane, Dan and Jane Stancill. 2003. “UNC building projects advance.” Raleigh News & Observer, July 15.
Monet, Claude. 1885. i>Meadow with Haystacks at Giverny, oil on canvas (Museum of Fine Arts, Boston). ARTstor.
Li, Albert P., and Robert H. Heflich, eds. 1991. Genetic toxicology. Boca Raton: CRC Press.
Rathgeb, Jody. 1997. “Taking the heights.” Civil War Times Illustrated 36 (6): 26-32, Academic Search Premier (9185).
Reid, P. H. 2001. “The decline and fall of the British country house library.” Libraries & Culture 36 (2): 345-366.
Scholz, Christopher H. 2002. The mechanics of earthquakes and faulting. New York: Cambridge University Press.

Single author

Nicholas, F.  2010. Introduction to Veterinary Genetics. 3rd ed. Oxford: Wiley-Blackwell.

Two authors
Rosenfeld, Andrew J., and Sharon M. Dial. 2010. Clinical Pathology for the Veterinary Team. Aimes, IA: Wiley-Blackwell.

Three or more authors
Millon, Theodore, Roger Davis, Carrie Millon, Luis Escovar, and Sarah Meagher. 2000. Personality Disorders in Modern Life. New York: Wiley.

Edited work
Butler, J. Douglas, and David F. Walbert, eds. 1986. Abortion, Medicine and the Law. New York: Facts on File Publications.

If the city of publication is not abbreviated, if city is unknown to readers or may be confused with another city of the same
name, the abbreviation of the state, province, or (sometimes) country is
usually added.

city: publisher


city, StateOrCountryAbbr: publisher

Woodward, K. N., ed. 2009. Veterinary Pharmacovigilance: Adverse Reactions to Veterinary Medicinal Products. Chichester, UK: Wiley-Blackwell.

Later edition
Ettinger, Stephen J., and Edward C. Feldman, eds. 2010. Textbook of Veterinary Internal Medicine: Diseases of the Dog and the Cat. 7th ed. St Louis: Elsevier Saunders.

No date of publication
Bligh, Beatrice. n.d. Cherish the Earth. Sydney: Macmillan.

Two or more books by the same author published in the same year
Gilbert, Sandra M. 1972a. Acts of Attention: The Poems of D. H. Lawrence. Ithaca: Cornell University Press.

Gilbert, Sandra M. 1972b. Emily’s Bread: Poems. New York: Norton.

Multivolume work
Russell, Bertrand. 1967. The Autobiography of Bertrand Russell. 3 vols. London: Allen & Unwin.

Proust, Marcel. 1970. Jean Santeuil. Translated by G. Hopkins. New York: Simon & Schuster.

Edited translation (where role of editor or translator is of chief importance)
West, T. G., ed. & trans. 1980. Symbolism: An Anthology. London: Methuen.

Ansett Transport Industries Ltd. 1984. Annual Report 1983-84. Melbourne: ATI.

Government publication
Australian Bureau of Statistics. 1985. Projections of the Population of Australia, States and Territories, 1984 to 2021, Cat. no. 3222.0. Canberra: ABS.

Government departments
Australia. Department of Aboriginal Affairs. 1989. Programs in Action for Aboriginal and Torres Strait Islander People: Achievements. Canberra: AGPS.

Newspaper article

Marshall, Tyler. “200th Birthday of Grimms Celebrated.” Los Angeles Times, 15 March 1985, sec. 1A, p. 3.


***The parentheses that enclose a text citation may also include a comment, separated from the citation by a semicolon.

(Mandolan 2009; t-tests are used here)

Western Australia. Environmental Protection Authority. 1998. Industrial Infrastructure and Harbour Development, Jervoise Bay. Bulletin 908. Perth: EPA.

Please Note: Documents authored by government departments are cited following the jurisdiction they report to. Precede the department name with Australia., Western Australia., etc.


How to construct an in-text parenthetical reference

The author-date citation in the text must correspond exactly to its full citation in the reference list.

  • Basic form. Include the author’s last name and year of publication.
       (Cox 1997)
  • Two authors with the same last name. Add a first initial to distinguish between the two.
       (M. Cox 1997)
  • Citation of a specific page or section. Insert a comma after the date and then give page number. Always include page number for direct quotations.
       (Cox 1997, 21)
  • Two publications by the same author in the same year. Use “a” and “b” to differentiate between the two.
       (Cox 1997a) and (Cox 1997b)
  • Two or three authors. Include all names in the citation.
       (Cox, Cunningham, and Hatleberg 1997)
  • More than three authors. Include the first name, followed by “et al.” (meaning “and others”).
       (Cox et al. 1997)
  • Multiple references in the same citation. Separate the citations with semicolons.
       (Cox 1997; Cunningham 1996; Hatleberg 1996)



In the Chicago Manual of Style 16, Chapter 15 is related to Author-Date

15.3 Notes and bibliography entries as models for author-date references. Most of
the examples in chapter14 are readily adapted to the author-date style-in
almost all cases by a different ordering or arrangement of elements.

Most reference list entries are identical to entries in a bibliography except for
the position of the year of publication, which in a reference list follows the
author’s name.

Unlike bibliography entries (see 14.59), each entry in the
reference list must correspond to a work cited in the text.

Text citations differ from citations in notes by presenting only the author’s last name
and the year of publication, followed by a page number or other locator, if any. This chapter, by focusing on these and other differences, will
allow readers to adapt any of the examples in chapter 14 to the authordate system.

14.157 Abbreviations for “page,” “volume,” and so on.

In citations, the words page, volume, and the like are usually abbreviated and often simply omitted (see 14.158 ).

The most commonly used abbreviations are

p. {pl. pp. ),

pt. ,

chap. , bk.,

sec. ,

n. {pl. nn. ), no., app., and fg. ; for these and others, see
10, especially 10.43.

Unless following aperiod, all are lowercased,

Burt, Ronald S. 1992.  “The Network Structure of Socia Capital.” Pp. 345-423 in Reseach in Oranizational Behavior, vol. 22, edited by Robert J. Sutton and Barry M . Stw. Greenwich, Conn.: Elsevier Science

and none is italicized unless an integral part of an italicized book title.
All the abbreviations mentioned in this paragraph, except for
p. and n.,
form their plurals by adding
s .

A Cry ofAbsence, chap. 6

Burt, Ronald S. 1 992.  “The Soial Capital of Structural Holes.” Chap. 7 in New Dirrtions in EcoKmic Sociology, edited by Mauro F. Guillen, Randall Collins, Paula England, and Marshall Meyer. New York: Russell Sage.

A Dance to the Music of Time, 4 vols.

14 . 158 When to omit “p.” and “pp.”

When a number or a range of numbers clearly denotes the pages in a book, p. or pp. may be omitted; the numbers alone, preceded by a comma, are sufficient.

Where the presence of other numerals threatens ambiguity, p. or pp. may be added for clarity.

(And if an author has used p. and pp. consistently throughout a work, there is no
need to delete them. )

Charlotte’s Web, 75-76
but p. is necessary
Complete Poems ofMichelangelo,
p. 89, lines 135-36

14.159 When to omit “vol.” When a volume number is followed immediately by
a page number, neither vol. nor
p. or pp. is needed. The numbers alone are
used, separated by a colon. A comma usually precedes the volume number, except with periodicals (see
14.180; see also 14.181) and for certain
types of classical references (see
14.256-66). For more on volume numbers, see 14.121-27. For citing a particular volume, with and without the
abbreviation vol., see

The Complete Tales ofHenry James, 10:122

14.160 Page and chapter numbers. Page numbers, needed for specifc references
in notes and parenthetical text citations, are usually unnecessary in bibliographies except when the piece cited is a part within a whole (see
or a journal article (see 14.183). If the chapter or other section number
is given, page numbers may be omitted. The total page count of a book is
not included in documentation. {Total page counts do, however, appear
Books 14.164
in headings to book reviews, catalog entries, and elsewhere. For book review headings, see 1.92. )
14. Claire Kehrwald Cook, “Mismanaged Numbers and References,” in Line by
Line: How to Edit Your Own Writing
(Boston: Houghton Mifin, 1985), 75-107.
15. Nuala O’Faolain,
Are You Somebody? The Accidental Memoir of a Dublin
(New York: Holt, 1996}. chap. 17.




Notes/Bibliography Chicago Style consists of two parts:

  1. A superscript number in the text and corresponding note
  2. A bibliography



9.3An alternative rulezero through nine

Many publications, including those in scientific or journalistic contexts, follow the simple rule of

spell out only single-digit numbers and use numerals for all others

  • My house is three years old.
  • According to a recent appraisal, my house is 103 years old.
  • The official attendance at this year’s fair was 47,122.

9.5 When a number begins a sentence, it is always spelled out.

One hundred ten candidates were accepted.

9.6 Ordinals

The general rule applies to ordinal as well as cardinal numbers. 

for example, 122nd and 123rd. The letters in ordinal numbers should not appear as superscripts .

Gwen stole second book in the top half of the first inning.

She found herself in 125th position out of 360.

9.18 Percentages

Except at the beginning of a sentence, percentages are usually expressed in numerals. In nontechnical contexts, the word percent is generally used; in scientific and statistical copy, the symbol % is more common.

Fewer than 3 percent of the employees used public transportation.
With 90–95 percent of the work complete, we can relax.
Only 20% of the ants were observed to react to the stimulus.
The treatment resulted in a 20%–25% increase in reports of night blindness.