MLA

Bryher, 1894-1983. Schaffner, Nicholas. Box 55, folder 2017-2018. 1966-71, n.d.. https://collections.library.yale.edu/catalog/17466072.

APA, 6th edition

Bryher, 1894-1983. (["Box 55, folder 2017-2018"])(1966-71, n.d.)[Schaffner, Nicholas]. https://collections.library.yale.edu/catalog/17466072.