MLA

Berberova, N. (Nina), 1901-1993. Janecek, Gerald. Box 11, folder 262-264. 1973-89, n.d.. https://collections.library.yale.edu/catalog/32324851.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 11, folder 262-264"])(1973-89, n.d.)[Janecek, Gerald]. https://collections.library.yale.edu/catalog/32324851.