Cite

Copland, Aaron [by George Platt Lynes]

MLA

Stein, Gertrude, 1874-1946. Copland, Aaron [by George Platt Lynes]. Box 170, folder 4347. n.d.. https://collections.library.yale.edu/catalog/11692122.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 170, folder 4347"])(n.d.)[Copland, Aaron [by George Platt Lynes]]. https://collections.library.yale.edu/catalog/11692122.