The Chicago Manual of Style (currently on its 18th edition) is one of the most widely used and respected style guides, offering comprehensive guidelines on grammar, punctuation, citation, and manuscript preparation. It features two primary citation styles: the author-date system, commonly used in the sciences and social sciences, and the notes and bibliography system, preferred in the humanities, especially in history and literature.
The Chicago Manual of Style, 18th Edition
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What’s new in the 18th edition?
The latest edition was released in 2024 and introduces several key updates, including expanded guidance on citing digital and online sources (e.g. podcasts, social media posts, online video, etc). There are also updates to the rules for punctuation, capitalization, and gender-neutral language, reflecting current trends in usage. A notable change is the updated approach to citing publishers—city names are no longer required for most publisher listings, except in cases where the publisher is not well known or could be confused with another entity.
What’s the difference between the author-date and notes and bibliography styles?
The author-date style is used primarily in the sciences and social sciences, focusing on in-text citations that include the author’s last name and publication year (e.g., Smith 2020). The full citation appears in a reference list at the end of the paper. The notes and bibliography style is commonly used in the humanities, especially in history and literature. It relies on footnotes or endnotes for citations, with a bibliography listed at the end of the document. This style is more flexible, allowing for more detailed source information in the notes.
How do I cite a source that I found in another source (a secondary citation)?
In the notes and bibliography style, a secondary citation would look like this in a note:
The author-date style allows you to cite it directly with a reference to the original author and a mention of the secondary source.
For example:
Jones, 2018, quoted in Smith, 2020, 45.
Make sure to include both the original and secondary sources in your bibliography.
How do I cite a website with no author?
You need to work with what you have! Double check to see if more information is available for a more complete citation. If not, when citing a website with no author, begin with the title of the page or article (it often appears in the tab at the top of the browser). In both styles, always include the full URL.
In the notes and bibliography style, it would appear as:
In the author-date style, the citation format would look like this:
Interesting Web Page. 2020. https://www.interestingwebpage.com/cool-page.
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