MLA

Loud, Lance, 1951-2001. Petit Bon Bons. Box 2. 1973, undated. https://collections.library.yale.edu/catalog/30996491.

APA, 6th edition

Loud, Lance, 1951-2001. (["Box 2"])(1973, undated)[Petit Bon Bons]. https://collections.library.yale.edu/catalog/30996491.