MLA

Brodsky, Joseph, 1940-1996. Peter Viereck Papers. Box 193, folder 4247. 1970-1997. https://collections.library.yale.edu/catalog/9998387.

APA, 6th edition

Brodsky, Joseph, 1940-1996. (["Box 193, folder 4247"])(1970-1997)[Peter Viereck Papers]. https://collections.library.yale.edu/catalog/9998387.