MLA

Bryher, 1894-1983. Robeson, Essie. Box 170, folder 5669. 1930, n.d.. https://collections.library.yale.edu/catalog/10187083.

APA, 6th edition

Bryher, 1894-1983. (["Box 170, folder 5669"])(1930, n.d.)[Robeson, Essie]. https://collections.library.yale.edu/catalog/10187083.