MLA

Bryher, 1894-1983. Colette. Box 7, folder 280. n.d.. https://collections.library.yale.edu/catalog/10167569.

APA, 6th edition

Bryher, 1894-1983. (["Box 7, folder 280"])(n.d.)[Colette]. https://collections.library.yale.edu/catalog/10167569.