MLA

Berberova, N. (Nina), 1901-1993. In Europe. Box 53, folder 1201. ca. 1939-47, n.d.. https://collections.library.yale.edu/catalog/10454091.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 53, folder 1201"])(ca. 1939-47, n.d.)[In Europe]. https://collections.library.yale.edu/catalog/10454091.