MLA

Stein, Leo, 1872-1947. Basler, Adolphe. Box 3, folder 68. 1926-34, n.d.. https://collections.library.yale.edu/catalog/17155341.

APA, 6th edition

Stein, Leo, 1872-1947. (["Box 3, folder 68"])(1926-34, n.d.)[Basler, Adolphe]. https://collections.library.yale.edu/catalog/17155341.