MLA

Berberova, N. (Nina), 1901-1993. Freidin, Gregory. Box 8, folder 189. 1979. https://collections.library.yale.edu/catalog/16687997.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 8, folder 189"])(1979)[Freidin, Gregory]. https://collections.library.yale.edu/catalog/16687997.