MLA

Berberova, N. (Nina), 1901-1993. Livshitz, Lev. Box 13, folder 343. n.d.. https://collections.library.yale.edu/catalog/16688017.

APA, 6th edition

Berberova, N. (Nina), 1901-1993. (["Box 13, folder 343"])(n.d.)[Livshitz, Lev]. https://collections.library.yale.edu/catalog/16688017.