The Chicago Manual of Style, 18th Edition presents a citation and format style, often referred to as Chicago, that is primarily used in professional publications and academic writing, including history and the humanities. Turabian style, outlined in A Manual for Writers of Research Papers, Theses, and Dissertations, is a simplified version of Chicago designed for undergraduate academic writing. Note: This handout will be updated upon the release of the new Turabian manual.
There are two primary Chicago and Turabian in-text citation styles: author-date and notes and bibliography. The difference between these two styles involves how to cite specific sources: author-date indicates the source of cited material using in-text parentheses and a corresponding reference list (like APA). Notes and bibliography uses a system of notes (footnotes or endnotes), which contains the citation information in the notes, paired with a full bibliography at the end.
This handout provides a basic outline of the author-date citation style and format. Throughout the handout, Chicago and Turabian are cited (by the letters C and T, respectively, along with applicable section numbers), so readers can refer to the manuals for more information. While this handout covers general concepts, always work with your audience and assignment in mind.
Page numbers should be included and placed consistently, generally in one of four locations: (1) centered in the footer, (2) centered in the header, (3) flush right in the footer, or (4) flush right in the header.
For the body of the paper, use a standard font such as 12-point Times New Roman or 10-point Arial. In general, use a smaller size font (10- or 11-point) for notes.
Double-space the text and leave a one-inch margin on all sides of the document. Indent the first line of each paragraph. For student papers, Turabian recommends single-spaced footnotes, endnotes, block quotes, and reference lists. Professional publications may adhere to different Chicago formatting guidelines.
Section headings or subheadings can be used to title different sections of a paper. Organizing a paper with titled sections helps readers understand the structure of your argument, especially for longer papers. Indicate higher or lower-level headings with boldface, italics, centering, and title caps, though Chicago is flexible with this format. Here is a possible example:
| First Level: centered, bold or italics, title caps | The Problem of Universals in Medieval Philosophy |
|---|---|
| Second Level: centered, regular type, title caps | William of Ockham’s View of Universals |
| Third Level: left-aligned, regular type, title caps | Universals in Ockham’s Political Philosophy |
Longer quotations (e.g., multi-paragraph quotations or 100+ word quotations) should be formatted as block quotes. Block quotes are indented from the left, generally by 0.5 inches (the same as a regular paragraph indent) with no extra first-line paragraph indent. In Turabian, block quotes are single-spaced and start on their own line with no quotation marks. Include a blank line before and after the block quote. In author-date format, a parenthetical in-text citation follows the final punctuation mark of the block quote. Text following a block quote should not be indented unless it begins a new paragraph.
Figures or illustrations can be placed in the body of the text to convey information in a more graphical manner or to reproduce an image for the reader’s convenience. Figures should be referenced in-text by the phrase Figure X (e.g., “Figure 3 shows that . . .”). Figures should be positioned close to their in-text reference. They should also be captioned, generally flush left beneath the image, with the word Figure and a number corresponding consecutively to the figures in the paper. This is followed by a short description of the figure (see Figure 1).
Figure 1. NASA Insignia. Design by James Modarelli, 1959. NASA.
In general, information about artwork (e.g., photographs, paintings, etc.) is included in the text but may also appear in the reference list. Artwork can be cited by the source (like a book or website) in which they were found or by the museum in which they are housed (see C 14.133).
Regardless of citation style, citing sources is a necessary and important part of academic writing because it allows writers to distinguish between their own work and the work of other authors. If writers do not acknowledge another author’s work, they commit plagiarism, which may have serious consequences.
The author-date system uses parenthetical citations to indicate the source of a particular quote, idea, or piece of information. These parenthetical citations correspond to a reference list at the end of the paper.
In author-date format, parenthetical citations generally have three components: the author’s last name, the year of publication, and page numbers of referenced material. This information is enclosed in parentheses, usually at the end of the sentence containing cited information. However, if the author’s name is used within the sentence, follow their name with the year of publication in parentheses, and include any page numbers in parentheses at the end of the sentence.
Parenthetical citations may be punctuated differently depending on the number and type of authors.
| Parenthetical Citation | Notes | |
|---|---|---|
| One author | (Jones 2021, 62) | |
| Two authors | (Duffin and Wimmer 2015, 96) | Write out both last names. |
| Three or more authors | (Schmidt et al. 2021, 79) | Write the first author’s last name and use et al. |
| Organization as author | (Snow College 2023, 88) | Use the organization’s name in place of the author’s name. Abbreviate if necessary; if so, begin the reference list citation with the abbreviation. |
Use a semicolon to separate two sources cited in the same sentence.
When citing the same page range of a source in a single paragraph, only include a full in-text citation after the last reference or at the end of the paragraph. If using different pages of the same source in one paragraph, use a full in-text citation after the first reference and include only the different page numbers in any subsequent references.
Sometimes sources are missing certain information, such as the name of the author or the publication date. With missing authors, leave the space blank and use the title of the piece in its place. With a missing publication date, use the acronym n.d. (‘no date’) in place of the date. Otherwise, the general rule is to skip the missing piece of information. These guidelines also apply to reference list citations.
Chicago discourages citing secondary or indirect sources, which occurs when material from one source is quoted in another source. However, if unable to locate the original source, provide a full citation of the secondary source on the reference list, and include the original source as part of the in-text citation.
Unpublished personal communication or interviews should be cited in text and accompanied by context and speaker information. Parenthetical citations include the interviewee name, form of communication, and date. A full reference citation is generally not required.
When citing AI-generated content, provide in-text information about the AI (including version number), how it was used, and the date the content was generated. Do not cite AI-generated content in a reference list unless it is required, and a URL is publicly available.
The author-date system uses a reference list at the end of the paper that contains information about the sources used throughout the paper. Reference citations correspond with in-text citations.
In the author-date system, the reference list is formatted differently from the rest of the text, as follows:
Note: If citing multiple sources by the same author, list the author’s name in the first entry. In subsequent entries, insert a 3-em dash in place of the author’s name (C 13.113; 18.2.1.1).
Chicago and Turabian require different information to appear in reference list citations depending on the type of source being used. A list of sample reference citations is provided below. Note: In 18th Edition, Chicago has advised against the inclusion of publisher location unless contextually necessary.
For seven or more authors, list the first three authors followed by et al.
While a page range is not included in the reference citation, page numbers should be included in the corresponding in-text citation.
While Chicago notes that webpage and website citation information may be primarily included in text, a formal reference citation may be included on a reference list.
