MLA

Berberova, N. (Nina), 1901-1993. Brik, Lili. Box 54, folder 1228. 1901. https://collections.library.yale.edu/catalog/10454439.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 54, folder 1228"])(1901)[Brik, Lili]. https://collections.library.yale.edu/catalog/10454439.