Headlines and Titles of Works
Q. For a book title within a book title in a language other than English, should quotation marks be inserted around the title within the title, just as we would for English-language titles (per CMOS 8.173)?
A. Usually, yes. For example, the French translation of Alice Kaplan’s Looking for “The Stranger” (Chicago: University of Chicago Press, 2016), like the English original, presents the title of Camus’s famous book in italics on its cover:
En quête de L’Étranger
To mention or cite this title in Chicago style, you would put the whole title in italics and add quotation marks (as for the English-language version), as in the following example of a bibliography entry (which retains the alternative French style for capitalizing titles as discussed in CMOS 11.27):
Kaplan, Alice. En quête de “L’Étranger.” Translated by Patrick Hersant. Paris: Gallimard, 2016.
Books in French or Spanish may use guillemets (« ») instead of italics for a title within a title; books in German may use reverse guillemets (» «) or inverted quotation marks („ “); other languages may follow similar conventions. You can convert such marks to English-style quotation marks (per CMOS 11.7). But if the title within a title isn’t differentiated as such on the cover (or title page) in any discernible way, and unless you are familiar with the conventions of the original language, it may be best to reproduce the title without adding quotation marks.