MLA

Berberova, N. (Nina), 1901-1993. Vainshtein, Mikhail. Box 21, folder 596. 1980-82, n.d.. https://collections.library.yale.edu/catalog/16688043.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 21, folder 596"])(1980-82, n.d.)[Vainshtein, Mikhail]. https://collections.library.yale.edu/catalog/16688043.