MLA

Stein, Gertrude, 1874-1946. Lecture announcement. Box 66, folder 1182. 1934 Oct 30. https://collections.library.yale.edu/catalog/14728447.

APA, 6th edition

Stein, Gertrude, 1874-1946. (["Box 66, folder 1182"])(1934 Oct 30)[Lecture announcement]. https://collections.library.yale.edu/catalog/14728447.