MLA

Thayer, Scofield, 1889-1982. Loy, Mina. Box 34, folder 948. 1921. https://collections.library.yale.edu/catalog/17142317.

APA, 6th edition

Thayer, Scofield, 1889-1982. (["Box 34, folder 948"])(1921)[Loy, Mina]. https://collections.library.yale.edu/catalog/17142317.