MLA

Berberova, N. (Nina), 1901-1993. By Kathleen Blumenfeld. Box 53, folder 1188. 1989-92. https://collections.library.yale.edu/catalog/10453953.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 53, folder 1188"])(1989-92)[By Kathleen Blumenfeld]. https://collections.library.yale.edu/catalog/10453953.