I can’t find a clear answer to this in style guides (it’s not a citation for an endnote or footnote, but just to include in a text). When attributing a quote made by a fictional character in a novel/play, do you attribute it to the character or to the author of the work? For example, would you write:
“Tomorrow is another day.” Scarlett O’Hara
OR
“Tomorrow is another day.” Margaret Mitchell
(Assume that it’s a much lesser known work than GWTW and not everybody will know who Scarlett O’Hara was.)\
IANA stylist, nor journalist, nor anyone professionally qualified to comment on this matter. But if I may, a suggestion? In contexts where it isn’t already obvious, you could use something like
“Tomorrow is another day.” --Scarlett O’Hara, in Margaret Mitchell’s Gone with the Wind
I agree that this probably isn’t necessary for the above-mentioned quote, or for Shakespeare, and you could likewise get away with less if you’re in a discussion about a particular work or author (for instance, in a Lord of the Rings thread, I might attribute a quote to simply “Gandalf”). But when in doubt, avoid ambiguity.
I frequently circumlocute the issue by doing part of the attribution in the introduction. As long as one is judicious in their usage, this can make things read much more smoothly. For example,
As Scarlett O’Hara said, “Tomorrow is another day.” [citation to book here] Of course, this looks less epigraphic, but it can be a nice change of pace. I agree with Chronos that in many cases you will need to be more specific about the source of the quote.