MLA

Thayer, Scofield, 1889-1982. Thayer, Florence. Box 44, folder 1237-1245. 1925-31, n.d.. https://collections.library.yale.edu/catalog/11371937.

APA, 6th edition

Thayer, Scofield, 1889-1982. (["Box 44, folder 1237-1245"])(1925-31, n.d.)[Thayer, Florence]. https://collections.library.yale.edu/catalog/11371937.