MLA

Gascoyne, David, 1916-2001. Scott, Roger. Box 9, folder 136-137. 1996-99. https://collections.library.yale.edu/catalog/2055495.

APA, 6th edition

Gascoyne, David, 1916-2001. (["Box 9, folder 136-137"])(1996-99)[Scott, Roger]. https://collections.library.yale.edu/catalog/2055495.