MLA

Thayer, Scofield, 1889-1982. Unidentified. Box 46, folder 1306. 1914-22, n.d.. https://collections.library.yale.edu/catalog/17142326.

APA, 6th edition

Thayer, Scofield, 1889-1982. (["Box 46, folder 1306"])(1914-22, n.d.)[Unidentified]. https://collections.library.yale.edu/catalog/17142326.