MLA

Stein, Gertrude, 1874-1946. Holograph drafts. Box 26, folder 534-536. n.d.. https://collections.library.yale.edu/catalog/2067425.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 26, folder 534-536"])(n.d.)[Holograph drafts]. https://collections.library.yale.edu/catalog/2067425.