Citation, Documentation of Sources
Q. How do I cite a single-volume book that contains two books by two different authors but with one editor? (This is a contemporary publication of two eighteenth-century novellas.)
A. Even such a book must have a title, so you may cite it as you would any other book that has an editor and no author (CMOS 14.87). In the unusual case that there is no collective title—that your work consists of two works bound together—just do your best to describe the work:
Author A, Title A, and Author B, Title B (City: Publisher, date).
Author A, Title A (City: Publisher, date), and Author B, Title B (City: Publisher, date). Bound as a single volume.
In a bibliography, add a cross-reference under Author B: see Author A.