MLA

Berberova, N. (Nina), 1901-1993. Nappelbaum, Ida. Box 46, folder 1072. 1986-92, n.d.. https://collections.library.yale.edu/catalog/17305294.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 46, folder 1072"])(1986-92, n.d.)[Nappelbaum, Ida]. https://collections.library.yale.edu/catalog/17305294.