Citing Your Sources: Chicago: Author-Date (17th)

The Williams Honor System requires you to properly acknowledge sources you have used in course assignments. This guide provides basic information on how to cite sources and examples for formatting citations in common citation styles.

CMOS 18 is Coming

Get Excited. CMOS 18 will be released September 2024. Updates to this guide will be made when changes to the style are made public. 

Chicago Author-Date

About Chicago 17th ed.: Author-Date

The Chicago Manual of Style Author-Date system is used by scholars in the social sciences and sciences. For arts, history, and humanities, see the Notes/Bibliography system.

Citing sources in this style consists of two parts:

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

The in-text citation points the reader to the full information about the source found in the reference list.

See How to Format In-Text Citations, How to Format the Reference List, and the examples of types of sources in the left navigation for further details.

How to Format In-Text Citations

An in-text citation provides your reader with two pieces of information:

  1. The the last name of the author(s) used in the corresponding reference list entry
  2. The year the work was published

Standard Formatting of the In-Text Citation

For more detailed information see Chicago Manual of Style, 15.21-15.31.

  • Enclose the author's last name and the year of publication in parentheses with no intervening punctuation.
    (Smith 2016)
  • For no author, see the "How do I deal with ____?" section.
  • For two to three authors, include the last names of authors using commas and and
    (Smith, Lee, and Alvarez 2016)
  • For four or more authors, include the last name of the first author and et al.
    (Smith et al. 2016)
  • When editors, translators, or compilers are used as the author, do not include their role (trans., ed., comp.) in the in-text citation.
  • When the reference list has works by authors with same last name, include their first initial in the in-text citation
    (B. Smith 2016)
    (J. Smith 2009)
  • If an author has published multiple works in the same year, alphabetize the titles in the reference list and then add a, b,c, etc. to the year
    (Lee 2015a)
    (Lee 2015b)
  • To cite specific page(s), add a comma and the page number(s)
    (Smith 2016, 21-23)
  • If the author's name appears in the sentence, do not include the name again in the parentheses
    Smith (2016) indicates that good citation practices are important.
  • To cite more than one reference in a single in-text citation, separate the references by semicolons. If the works are by the same author, use just the year and separate with a comma. See CMOS 15.30 for details.
    (Smith 2016; Lee 2015)
    (Smith 2016, 2013; Lee 2015)

How to Format the Reference List

General Formatting of the Reference List

For more detailed information see Chicago Manual of Style, 15.10-15.20

The reference list provides the full details of the items you have cited in your paper. Here are some general features of the reference list:

  • Usually titled References or Works Cited
     
  • Entries begin with author(s) and date of work; other required elements depend on the type of source. See examples in the left navigation.
     
  • Entries are arranged alphabetically by the last name of the first author
    • alphabetize using the letter-by-letter system, in which an entry for “Fernández, Angelines” would come before the entry for “Fernán Gómez, Fernando” (d in "Fernández" comes before G in "Gómez")
       
  • If there is no author, use the first word of the title of the work (excluding The, A, An).
     
  • Single-author entries precede multiauthor entries beginning with the same name.
     
  • Multiple works by the same author(s) are arranged chronologically, and the 3-em dash replaces the name for the second and subsequent entries.

    Du Bois, W. E. B. 1898. "The Study of the Negro Problems." Annals of the American Academy of Political and Social Science 11 (January): 1-23. http://www.jstor.org/stable/1009474.

    ———. 1903. The Souls of Black Folk: Essays and Sketches. Chicago: A. C. McClurg.

    ———. 1947. The World and Africa: An Inquiry into the Part Which Africa Has Played in World History. New York: Viking.
     

  • Multiple works by same author in same year are arranged alphabetically by title, and then a, b, c, etc. is added to the year to help make each entry unique for the in-text citation.

    Olney, William W. 2015a. "Impact of Corruption on Firm-Level Export Decisions." Economic Inquiry 54 (2): 1105–27.

    Olney, William W. 2015b. "Remittances and the Wage Impact of Immigration." Journal of Human Resources 50 (3): 694-727.

How do I deal with ___?

Missing citation elements

  • Author:
    • If no personal author is listed, determine whether an organization is responsible for the content. If so, use that organization's name as the author in the reference list and in-text citation. (CMOS, 15.36)

      (World Bank 2011)

      World Bank. 2011. Poverty and Social Exclusion in India. Washington, DC: World Bank.
    • If a newspaper article is unsigned, use the newspaper title as the author. (CMOS, 15.49)

      (New York Times 1912)

      New York Times. 1912. "Titanic Sails To-Day." April 10, 1912.
    • If the author is unknown, start the reference list entry with the title. For the in-text citation, use the title, which can be shortened as long as the first word matches the reference list entry (CMOS15.34)

  • Date: If there is no publication or last modified date, use n.d. (CMOS, 15.44 and 15.50

    (Human Rights Campaign, n.d.)

    Human Rights Campaign. n.d. "Maps of State Laws and Policies." Accessed April 25, 2019. http://www.hrc.org/state_maps.
  • Page numbers: For unpaginated works, such as online resources, include a descriptive phrase using one of the divisions used in the work (chapter, paragraph number, section heading, etc.) in the in-text citation. If the work is short, such locators may not be necessary. (CMOS, 15.23)

    (Library of Congress, n.d., under "Slave Narratives and the New Debate about Slavery")

    Library of Congress. n.d. "Slave Narratives from Slavery to the Great Depression." An Introduction to the WPA Slave Narratives. Accessed June 27, 2019. https://www.loc.gov/collections/slave-narratives-from-the-federal-writers-project-1936-to-1938/articles-and-essays/introduction-to-the-wpa-slave-narratives/slave-narratives-from-slavery-to-the-great-depression/.
  • Place: Use n.p. if it is unknown. If it can be surmised, put in brackets with a question mark. (CMOS, 14.132)
  • Publisher: If not listed on the title page or copyright page, use "self-published" or "printed by author." (CMOS, 14.137)

More than one author

  • List authors in order they appear on title page
  • In the reference list, invert the first author's name only and place a comma before and after the first name
  • Use the word "and," not an ampersand (&)
  • For works with 4-10 authors, list all names in the reference list, but only use the first author's name followed by et al. in the in-text citation.
  • For works with more than 10 authors, only include the first 7 authors and et al. in the reference list
    (CMOS15.9, 15.1615.2914.76)
Examples

In-text Citations:

(Geis and Bunn 1997, 17)

(Chih-Hung Ko et al. 2009, 600)

Reference List:

Geis, Gilbert, and Ivan Bunn. 1997. A Trial of Witches: a Seventeenth-Century Witchcraft Prosecution. London: Routledge.

Ko, Chih-Hung, Ju-Yu Yen, Shu-Chun Liu, Chi-Fen Huang, and Cheng-Fang Yen. 2009. "The Associations between Aggressive Behaviors and Internet Addiction and Online Activities in Adolescents." Journal of Adolescent Health 44 (6): 598-605.


Using a source quoted in a secondary source

It is always better to consult the original source, but if it cannot be obtained, give information about the original source in the running text and include "quoted in" in your in-text citation for the secondary source. Include only the secondary source in your reference list. (CMOS, 15.56)

In his 1844 book Thoughts on the Proposed Annexation of Texas to the United States, Theodore Sedgwick opines "The annexation of Texas instead of strengthening the Union, weakens it" (quoted in Rathbun 2001, 479).

Rathbun, Lyon. 2001. "The Debate over Annexing Texas and the Emergence of Manifest Destiny." Rhetoric & Public Affairs 4 (3): 459-493.

 

Examples: Books, Chapters

Book

For more information see: Chicago Manual of Style, 15.9, 15.40-15.45

Format

Author Last Name, First Name. Year. Book Title. Place: Publisher.

For e-books, include the provider of the book, the URL, or e-book application/device at the end of the citation. (CMOS,14.159-14.163)

Examples

Feder, Ellen K. 2007. Family Bonds: Genealogies of Race and Gender. Oxford: Oxford University Press. ProQuest ebrary.

Nairn, Tom. 1997. Faces of Nationalism: Janus Revisited. London: Verso.

Stewart, K. J. 1864. A Geography for Beginners. Richmond: J. W. Randolph. http://docsouth.unc.edu/imls/stewart/stewart.html.


Edited Book

For more information see: Chicago Manual of Style, 15.9, 15.36

Format

Author Last Name, First Name, ed. Year. Book Title. Place: Publisher.

Example

Dmytryshyn, Basil, ed. 1999. Imperial Russia: A Source Book, 1700-1917. New York: Academic International Press.


Chapter or Essay in Book

For more information see: Chicago Manual of Style, 15.9, 14.106-14.112

Format
Author Last Name, First Name. Year. "Chapter/Essay Title." In Book Title, edited by Editor First Name Last Name, Inclusive Pages of Chapter/Essay. Place: Publisher.
Example

Roell, Craig H. 1994. "The Piano in the American Home." In The Arts and the American Home, 1890-1930, edited by Jessica H. Foy and Karal Ann Marling, 193-204. Knoxville: University of Tennessee Press.


Entry in a Reference Book

For more information see: Chicago Manual of Style, 14.23214.23314.234

Well-known encyclopedias and dictionaries are usually cited in the running text only. For other reference works, cite as a book or book chapter.

Examples: Articles

Journal Article

For more information see: Chicago Manual of Style, 15.9, 15.46

Format

Author Last Name, First Name. Year. "Article Title." Journal Title Volume (Issue): Page Range of Article. URL/DOI.

For journal articles consulted online, use a URL based on a DOI (begins with https://doi.org/). Otherwise, use the URL provided with the article.

Examples

Hunter, Margaret. 2016. "Colorism in the Classroom: How Skin Tone Stratifies African American and Latina/o Students." Theory into Practice 55 (1): 54-61. https://doi.org/10.1080/00405841.2016.1119019.

Thompson, Maxine S., and Keith Verna M. 2001. "The Blacker the Berry: Gender, Skin Tone, Self-Esteem, and Self-Efficacy." Gender and Society 15 (3): 336-57. http://www.jstor.org/stable/3081888.


Magazine Article

For more information see: Chicago Manual of Style, 15.49

Magazine articles can be cited in the running text (e.g., As Scott Spencer mentions in his May 1979 Harper's article "Childhood's End," ....) and not included in the reference list. However, if a formal citation is needed, follow the example below, repeating the year with the month and day.

Format

Author Last Name, First Name. Year. "Article Title." Magazine Title, Month Day, Year, Page Range of Article.

If citing an online magazine, end the citation with the URL, library database, or app.

Spencer, Scott. 1979. "Childhood's End." Harper's, May 1979, 16-19.

Tobar, Héctor. 2016. "Can Latinos Swing Arizona?" New Yorker. August 1, 2016. http://www.newyorker.com/magazine/2016/08/01/promise-arizona-and-the-power-of-the-latino-vote.

Tobar, Héctor. 2016. "Can Latinos Swing Arizona?" New Yorker (iPhone app). August 1, 2016.


Newspaper Article

For more information see: Chicago Manual of Style, 15.4914.191 - 14.200

Newspaper articles can be cited in the running text (e.g., As John Eligon mentioned in his November 18, 2015 New York Times article ....) and not included in the reference list. However, if your professor requires it, follow the examples below, repeating the year with the month and day.

Format

Author Last Name, First Name. Year. "Article Title." Newspaper Title, Month Day, Year. sec. Section.

Page numbers are not included because articles can appear on different pages in different editions. For regularly occurring columns, cite with both the column name and headline or just the column name. If citing an online newspaper, include the URL at the end. If citing from a library database, include the database name.

Examples

Eligon, John. 2015. "One Slogan, Many Methods: Black Lives Matter Enters Politics." New York Times, November 18, 2015. http://www.nytimes.com/2015/11/19/us/one-slogan-many-methods-black-lives-matter-enters-politics.html.

Erlanger, Steve. 1998. "Pact on Israeli Pullback Hinges on Defining Army's Role." New York Times, May 8, 1998, sec. A.

King, Martin Luther, Jr. 1966. "Negro Faces Dixie Justice." My Dream. Chicago Defender, April 23, 1966. ProQuest Historical Newspapers.

Examples: Web Pages, Blogs, Social Media

Web Page

For more information see: Chicago Manual of Style, 15.51, CMOS quick guide

Format

Author Last Name, First Name. Last Modified Year. "Page Title." Website Title. Last modified Month Day, Year. URL.

If there is no personal author, start with the page title or site sponsor. If there is no last modified date, use n.d.

Examples

DeSilver, Drew. 2018. "The Real Value of a $15 Minimum Wage Depends on Where You Live." Pew Research Center. Last modified October 10, 2018. http://www.pewresearch.org/fact-tank/2018/10/10/the-real-value-of-a-15-minimum-wage-depends-on-where-you-live/.

Human Rights Campaign. n.d. "Maps of State Laws and Policies." Accessed April 25, 2019. http://www.hrc.org/state_maps.

 


Blog Posts and Comments

For more information see: Chicago Manual of Style15.51 and 14.208

Blog posts and comments are generally cited in the running text and omitted from the reference list. If a reference list entry is needed, follow the example below.

Format

Author Last Name, First Name. Year. "Post Title," Blog Title (blog), Month Day, Year. URL.

If the blog has the word "blog" as part of its name, "(blog)" should not be included in the citation. If the blog is a part of a larger publication, include that title, too.

Example

Stewart, Jenell. 2016. "Natural Hair Creates a More Inclusive Standard," My Natural Hair Journey (blog), Huffington Post, July 12, 2016. http://www.huffingtonpost.com/jenell-stewart/natural-hair-creates-a-more-inclusive-beauty-standard_b_10949874.html.

 


Social Media

For more information see: Chicago Manual of Style, 14.209 and 15.52

Citations for social media content can often be incorporated into the text:

Reacting to the Obergefell v. Hodges decision, Obama tweeted, "Today is a big step in our march toward equality. Gay and lesbian couples now have the right to marry, just like anyone else. #LoveWins" (@POTUS44, June 26, 2015).

If you cite an account frequently or an extensive thread, use the format below for the reference list. Direct or private messages shared through social media are treated as personal communication (see COMS, 15.53).

Format
Author's Real Last Name, First Name (Screen name). Year. "up to 160 characters of text of post." Social Media Service Name, Month Day, Year. URL.

Use the screen name in the author position if there is no real name. If you have already fully quoted the text of the post, that element is not needed in the note. If relevant, include media type (photo, video, etc.) after the name of the social media service.

Example
Obama, Barack (@POTUS). 2015. "Today is a big step in our march toward equality. Gay and lesbian couples now have the right to marry, just like anyone else. #LoveWins." Twitter. June 26, 2015. http://twitter.com/POTUS/status/614435467120001024.

Examples: Music, Film, TV, Images

Note: In many cases media can be cited in the running text or grouped in a separate section or discography, but author-date style citation can be created by adapting the format used in the notes/bibliography style, moving the year to the second position. You can choose whom to list as the author depending on the focus of your citation. While you should always cite the format you used, the original date of the work, if known, should be privileged in the citation. (CMOS, 15.57)

Music Score

For more information see: Chicago Manual of Style, 14.255

Published music scores are cited like books and book chapters.

Format

Composer Last Name, First Name. Year. "Song Title." In Book Title, edited by Editor First Name Last Name, Inclusive Pages for Song. Place: Publisher.

Example

Johnson, Charles L. "Crazy Bone Rag." 1997. In Ragtime Jubilee: 42 Piano Gems, 1911-21, edited by David A. Jasen, 41-45. Mineola, NY: Dover Publications.


Music Recording

For more information see: Chicago Manual of Style, 14.263

Format

Performer or Conductor Last Name, First Name. Original Release Year. Album Title. Record Label Catalog Number, Year of Format Used, Medium or Streaming Service or File Format. 

Examples

The Beatles. 1970. Let it Be. Capitol 3 82472 2, 2009, compact disc.

Beyoncé. 2016. Lemonade, Parkwood Entertainment, MP3.


Film

For more information see: Chicago Manual of Style, 14.265

Format

bibliography:

Director First Name Last Name, dir. Original Film Release Year. Film Title. Place: Studio/Distributor, Release Year of Medium Used. Medium.

Example

Scott, Ridley, dir. 1991. Thelma & Louise. Santa Monica, CA: MGM Home Entertainment, 2004. DVD.


Online Video

For more information see: Chicago Manual of Style, 14.267

The format of citations depends on the information available. Generally, include details about the original published source (if applicable) and details related to the digitized copy such as source type, length, and where it is posted. See the two examples of format below.

Format

Video Creator Last Name, First Name. Original Release Year. Video Title. Original Production Company. From Provider of Online Video. Source Type, Running Time. URL.

Digitizing Organization. Original Year. "Video Clip Title." Source Type, Running Time. From Original Performance or Source Date. Posted Date. URL.

Examples

U.S. Federal Civil Defense Administration.1951. Duck and Cover. Archer Productions. From Internet Archive, Prelinger Archives. MPEG video, 9:15. http://archive.org/details/DuckandC1951.

John F. Kennedy Library Foundation. 1960. "TNC:172 Kennedy-Nixon First Presidential Debate, 1960." YouTube video, 58:34. From televised debate September 26, 1960. Posted September 21, 2010. http://www.youtube.com/watch?v=gbrcRKqLSRw.


Television

For more information see: Chicago Manual of Style, 14.265

Format

bibliography:

Director Last Name, First Name, dir. Year aired. TV Show Title., Season number, episode number, "Episode Title." Aired Month Day, Year, on Network. Medium or URL for online access.

Example

Silberling, Brad, dir. 2014. Jane the Virgin. Season 1, episode 1, "Chapter One." Aired October 13, 2014, on The CW. https://www.netflix.com/title/80027158.


Image

For more information see: CMOS Shop Talk

Images are usually not included in the reference list. In the running text or caption indicate the artist, year the work was created, title of the work, and where it is located.

Examples: Government Documents

For more information see: Chicago Manual of Style, 15.58 and 15.59

If you make extensive use of legal or government documents, cite them in the Chicago Notes format as supplementary footnotes instead of as in-text citations. See CMOS 15.31

If you are using just a few documents, cite them in the running text using the legal citation form recommended in The Chicago Manual of Style, 14.269-14.305 and in the Chicago Notes section of this guide.

In Griswold v. Connecticut (381 U.S. 479 (1965)), the court ruled that ...

In remarks about the DREAM Act on the Senate floor (156 Cong. Rec. S10259 (daily ed. December 15, 2010)), Senator Durbin discussed ...

 

Examples: Unpublished/Archival

Interview/Discussion

For more information see: Chicago Manual of Style, 15.48

Unpublished interviews are cited as an in-text citation only; they do not appear in the reference list.

  • In the parenthetical citation, put "personal communication" after the name of the person being interviewed.
    (Maud Mandel, personal communication)
  • For class discussions, put the course number, "class discussion," and the date of the class.
    (ECON 110 class discussion, April 19, 2019)

Manuscript/Archival Material

For more information see: Chicago Manual of Style, 15.49

Manuscript materials are cited in the running text indicating the date of the cited item and using the name of the manuscript collection in the in-text reference. 

Mark Hopkins wrote in a March 22, 1861 letter to Jaime Margalotti (Hopkins Family Papers) ...

The reference list provides details about the manuscript collection only, not the individual items.

If only one item from a collection is cited, the details of that item can be included in the reference list and the author used in the in-text citation.

Format

Collection Name. Repository Name. Place.

Author Last Name, First Name. Year of Item. Item Description. Month Day, Year of Item. Collection Name. Repository Name, Place.

If the item was accessed online, include the URL at the end of the citation.

Examples

Hopkins Family Papers. Williams College Special Collections. Williamstown, MA.

(Hopkins Family Papers)

Hopkins, Mark. 1861. Letter to Jaime Margalotti. March 22, 1861. Hopkins Family Papers. Williams College Special Collections, Williamstown, MA.

(Hopkins 1861)

Need More Info?

What Needs to be Cited?

  • Exact wording taken from any source, including freely available websites
  • Paraphrases of passages
  • Summaries of another person's work
  • Indebtedness to another person for an idea
  • Use of another student's work
  • Use of your own previous work

You do not need to cite common knowledge.