Q. When citing a book, is it correct to list the state as part of the publication place, if it is not published in a major city? What about a city that shares a name with a more famous one, such as London, Ohio?
A. Include the state if you think it isn’t obvious. If the publisher is a state university, it’s obvious. Cincinnati is obvious; London, Ohio, is not. In many cases it will be a judgment call. The decision, like so many others in writing and editing, should not be made according to some idea of what is “correct.” Rather, it must be made according to what is logical and helpful.
[Editor’s update: A city of publication is no longer required in citations of books published since 1900. See paragraph 14.30 in the 18th edition of CMOS.]