MLA

Brodsky, Joseph, 1940-1996. Other sketches. Box 133, folder 2985. 1993, undated. https://collections.library.yale.edu/catalog/2107224.

APA, 6th edition

Brodsky, Joseph, 1940-1996. (["Box 133, folder 2985"])(1993, undated)[Other sketches]. https://collections.library.yale.edu/catalog/2107224.