Citation, Documentation of Sources

Q. I’ve noticed that print and e-book versions of the same title sometimes have different dates of publication; how should this be dealt with in bibliographic entries? If I were quoting from such a work, I would provide the publication date of whichever version, print or digital, I had consulted, but what about a reference that’s intended only to point the reader toward a certain resource (“for more on this topic, see Smith 2018”)? In that case, should preference be given to the earlier date over the later? To the print version over the digital?

A. Cite the year of whichever edition you choose to recommend. For e-books, include the format (Kindle, iBooks, etc.). You can see examples in our Citation Quick Guide, under “E-book > Reference-List Entries.”

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]