Chicago Manual of Style (CMS) Citation Format

The Chicago Manual of Style (CMS) is one of the most widely used citation systems in the United States, especially in the humanities, social sciences, and natural sciences. First published in 1906, its 17th edition (released in 2017) offers two primary documentation systems:

• Notes and Bibliography footnotes or endnotes paired with a bibliography. Preferred for literature, history, and the arts.
• AuthorDate parenthetical intext citations with a reference list. Common in the sciences and social sciences.

This page explains the core principles of both systems, shows how to cite the most frequent source types, and provides practical advice for students, researchers, and writers.

Basic Principles

1. Consistency

All citations must follow the same format throughout a document. Mixing elements from the two systems is not acceptable.

2. Completeness

A citation should give a reader enough information to locate the source instantly: author(s), title, publication information, and, when relevant, page numbers or DOI.

3. Punctuation and Italics

• Book and journal titles are italicized.
• Article, chapter, and webpage titles are placed in quotation marks.
• Use periods after each major element; commas separate subelements.

4. Capitalization

In titles, use headline style: major words capitalized, minor words (articles, conjunctions, prepositions) lowercase unless first or last word.

NotesBibliography System

In this system, the first citation of a source appears in a superscript number linked to a footnote (or endnote). Subsequent citations of the same work can be shortened. A bibliography at the end lists every source used, alphabetized by author.

Footnote/Endnote Format

1. Firsttime citation full details.
2. Subsequent citation shortened form (Authors Last Name, Short Title, page).
3. Multiple works by the same author use a 4dash line () after the first full citation.

Example: Book

First citation:

1. Emily Dickinson, Collected Poems (New York: Knopf, 1993), 45.

Subsequent citation:

2. Dickinson, Collected Poems, 102.

Example: Chapter in an Edited Book

3. Michael F. OBrien, Narrative Voice in Early American Fiction, in The American Novel, 17501800, ed. Jane Smith (Boston: Academic Press, 2005), 7880.

Example: Journal Article

4. Sarah K. Patel, Digital Preservation and the Humanities, Journal of Library Science 28, no. 3 (2019): 21530, https://doi.org/10.1234/jls.2019.028.

Bibliography Format

Each entry mirrors the firsttime footnote but with a hanging indent. Authors are listed with last name first, followed by a comma and first name.

Source Type	Bibliography Example
Book	Dickinson, Emily. Collected Poems. New York: Knopf, 1993.
Chapter in Edited Book	OBrien, Michael F. Narrative Voice in Early American Fiction. In The American Novel, 17501800, edited by Jane Smith, 7880. Boston: Academic Press, 2005.
Journal Article	Patel, Sarah K. Digital Preservation and the Humanities. Journal of Library Science 28, no. 3 (2019): 21530. https://doi.org/10.1234/jls.2019.028.
Website	World Health Organization. Global Air Quality Guidelines. Accessed March 12, 2024. https://www.who.int/airquality.

AuthorDate System

The authordate style places a parenthetical citation directly after the referenced material. The reference list (often called References) appears at the end, alphabetized by author.

InText Citation

General form: (Author Year, page). If no page is available, omit it.

• One author: (Doe 2022, 15)
• Two authors: (Doe and Roe 2021)
• Three or more authors: (Doe et al. 2020, 4546)

Reference List Entries

Source Type	Reference List Example
Book	Doe, Jane. 2022. Modern Urban Planning. London: Routledge.
Journal Article	Roe, John, and Alan Smith. 2021. Renewable Energy Policies in Europe. Energy Policy 78 (July): 11223. https://doi.org/10.1016/j.enpol.2021.03.004.
Online Report	United Nations. 2020. World Population Prospects 2020. New York: UN Department of Economic and Social Affairs. Accessed February 5, 2024. https://population.un.org/wpp/.

Citing Common Source Types

Books

NotesBibliography: FirstName LastName, Title (Place: Publisher, Year), page.

AuthorDate: LastName, FirstName. Year. Title. Place: Publisher.

Edited Volumes

Notes: FirstName LastName, Chapter Title, in Book Title, ed. Editor Name (Place: Publisher, Year), page.

AuthorDate: LastName, FirstName. Year. Chapter Title. In Book Title, edited by Editor Name, page range. Place: Publisher.

Journal Articles

Notes: FirstName LastName, Article Title, Journal Name Volume, no. Issue (Year): pagepage, DOI.

AuthorDate: LastName, FirstName. Year. Article Title. Journal Name Volume (Issue): pagepage. DOI.

Web Pages

Notes: FirstName LastName (if known), Page Title, Site Name, last modified Date, URL.

AuthorDate: LastName, FirstName. Year. Page Title. Site Name. Last modified Date. URL.

Legal Materials

Legal citations follow a specialized Chicago format (see 14 of the Manual). Example for a U.S. Supreme Court case:

5. Brown v. Board of Education, 347 U.S. 483 (1954).

Practical Tips & Helpful Tools

• Keep a master list. Record every source as you find it; this prevents missing citations later.
• Use citation generators cautiously. Tools like Zotero, Citavi, or the Chicago Manuals own online guide produce correct syntax most of the time, but always doublecheck against the official style guide.
• Mind the punctuation. A misplaced comma or period can change the meaning of a citation.
• Page numbers matter. For direct quotations, always include the specific page, even in authordate citations.
• URLs and DOIs. Prefer a DOI when available; otherwise, provide a stable URL and the date you accessed the material.
• Consistent abbreviation. Use the same abbreviation for journal titles throughout (e.g., J. Am. Hist. for *Journal of American History*).

Recommended Resources

1. The official Chicago Manual of Style website searchable PDF and quickreference guides.
2. Zotero free reference manager with a Chicago style output.
3. Purdue OWL clear examples for both CMS systems.

By understanding the underlying logic of Chicago styleclarity, completeness, and consistencyyoull be able to adapt to any source you encounter and produce scholarly work that meets professional standards.