Q. How do I write the citation for one work that is quoted in another work?

In academic or scholarly work, the writer is expected to get the original source of a quotation, if at all possible. In the case of a major author, like Shakespeare, the original text is widely available. The precise manner for citing an indirect quotation varies according to the citation style which you are following (MLA, APA, Chicago, etc.).  Below are some of the detailed guidelines.

MLA Handbook 6.4.7

Whenever you can, take material from the original source, not a secondhand one.  Sometimes, however, only an indirect source is available -- for example, someone's published account of another's spoken remarks. If what you quote or paraphrase is itself a quotation, put the abbreviation qtd. in ("quoted in") before the indirect source you cite in your parenthetical reference.

A Manual for Writers (Turabian) 17.10

Responsible researchers avoid repeating quotations that they have not actually seen in the original. If one source includes a useful quotation from another source, readers expect you to obtain the original to verify not only that the quotation is accurate, but also that it fairly represents what the original meant.

If the original source is unavailable, however, cite it as "quoted in" the secondary source in your note. For the bibliography entry, adapt the "quoted in" format as needed.

The same situation may arise with a quotation you find in a secondary source drawn from a primary source.  Often, you will not be able to consult the primary source, especially if it is in an unpublished manuscript collection.  In this case, follow the principles outlined above.

The Chicago Manual of Style 14.273

To cite a source from a secondary source ("quoted in . . .") is generally discouraged, since authors are expected to have examined the works they cite. If an original source is unavailable, however, both the original and the secondary source must be listed.

APA Style

To cite a source you find in another source, identify the secondary source in the parenthetical citation in this manner:

(Smith, as cited in Jones, 2015).

Identify the nature of the primary source (out-of-print, archival manuscript, oral history, interview, e-mail, etc.) in your text or any other reason why the original source is not available. Use the Jones source in your "References" list at the end of your paper. See this post from the APA website which explains the reasons why secondary sources are disfavored. "Secondary Sources (aka How to Cite a Source You Found in Another Source)." APA Style Blog, 28 July 2010.