MLA

Gascoyne, David, 1916-2001. "Blatant Invention," signed. Box 23, folder 410. undated. https://collections.library.yale.edu/catalog/2055218.

APA, 6th edition

Gascoyne, David, 1916-2001. (["Box 23, folder 410"])(undated)["Blatant Invention," signed]. https://collections.library.yale.edu/catalog/2055218.