"Whenever you can, take material from the original source, not a secondhand one. Sometimes, however, only an indirect source is available - for example, an author's published account of someone'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. (You may wish to clarify the relation between the original and secondhand sources in a note.)" (MLA Handbook, 8th ed. p. 124)
Lawrence Christy remarked that Lindsay Ryan had a "unique style of debate" (qtd. in Anderson 107).
For your list of works cited, give the indirect source (Anderson) not the source quoted (Christy).