For eBooks / books online, check the section Books / Chapters / Ebooks.
For articles, check the section Articles in Periodicals.
For most electronic sources, Chicago recommends the addition of a URL or DOI following the full facts of publication.
Websites (dated )
In the reference list, repeat the year with the month and day to avoid any confusion. No access date is required.
♦ ( Microsoft Corporation 2006)
Microsoft Corporation. 2006. "WD2000: Visual Basic Macro to Assign Clipboard Text to a String Variable.?"
Revision 1.3. Microsoft Help and Support. Last modified November 23, 2006. http://support.microsoft.com
/kb/212730.
Websites (undated)
Access date is given only if no date of publication or revision can be determined from the source and "n.d." (always in lowercase) is used in the place of publication date in the reference list and the in-text citation.
♦ (City of Sacramento, California, n.d.)
City of Sacramento, California. n.d."Apply for a Business Operation Tax Account (BOT)." Business. Accessed
June 1, 2020. https://www.cityofsacramento.org/Finance/Revenue/Business-Operation-Tax/Apply-for-
a-Business-Operation-Tax-Account.
Blogs (are cited similarly to online newspaper and magazine articles)
In reference list, repeat the year of publication with the month and day to avoid any confusion.
♦ (Paine and Thomson-DeVeaux 2020)
Paine, Neil, and Amelia Thomson-DeVeaux. 2020. "The Economists In Our Survey Are Slightly More Hopeful
Than They Were Two Weeks Ago." Politics (blog). FiveThirtyEight, June 9, 2020. https://fivethirtyeight.com
/features/the-economists-in-our-survey-are-slightly-more-hopeful-than-they-were-two-weeks-ago/.
Social Media (Citations can often be limited to the text)
In the reference list, include the real name and a screen name, if both are available. repeat the year of publication with the month and day to avoid any confusion.
♦ (O'Brien 2015)
O'Brien, Conan (@ConanOBrien). 2015. "In honor of Earth Day, I'm recycling my tweets." Twitter, April 22,
2015, 11.10 a.m. https://twitter.com/ConanOBrien/status/590940792967016448.
♦ (Chicago Manual of Style 2020)
Chicago Manual of Style. 2020. "Verbs are where the action is." Facebook, May 26, 2020.
https://www.facebook.com/ChicagoManual/posts/10157589174794151.
Unpublished interviews / personal communications
In a parenthetical citation, the terms "personal communication" or "pers.comm." , "unpublished data", and the like may be used after the name(s) of the person(s) concerned. Reference list entries are not needed, so each person cited must be fully identified elsewhere in the text.
♦ (Julie Cantor, pers. comm.)
♦ (Jonathan Lee, Facebook direct message to author, May 5, 2017)
♦ (John Smith, unpublished data)
Online document
♦ (Accelerate Cure Project 2006)
Accelerate Cure Project. 2006. “Analysis of Genetic Mutations or Alleles on the X or Y Chromosome
as Possible Causes of Multiple Sclerosis.” October 26, 2006. https://www.acceleratedcure.org/sites/default/files
/attachments/phase2-genetics-xy-chromosomes.pdf.
