MLA

Gould Adams Scratton, B. M. (Bride M.). Guggenheim, Peggy. Box 2, folder 65. 1954 Jan 9. https://collections.library.yale.edu/catalog/17209448.

APA, 6th edition

Gould Adams Scratton, B. M. (Bride M.). (["Box 2, folder 65"])(1954 Jan 9)[Guggenheim, Peggy]. https://collections.library.yale.edu/catalog/17209448.