How do I cite a quotation of another work used in the work that I'm reading?

Answer

You are asking about citing an indirect or secondary quote! Each citation style handles this situation differently. However, in all cases, you must cite both sources.

Attached are two links to instructions for this unusual type of citation in APA (7th) and Chicago Manual of Style (17th) citation styles, as well as a video demonstration of MLA (8th).