MLA

Bryher, 1894-1983. Ellerman, Hannah. Box 10, folder 408-411. 1934-39, n.d.. https://collections.library.yale.edu/catalog/17290820.

APA, 6th edition

Bryher, 1894-1983. (["Box 10, folder 408-411"])(1934-39, n.d.)[Ellerman, Hannah]. https://collections.library.yale.edu/catalog/17290820.