MLA

Steinberg, Saul, 1914-1999. Musical. Box 550 (Oversize), folder 7366. 1968. https://collections.library.yale.edu/catalog/12155857.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 550 (Oversize), folder 7366"])(1968)[Musical]. https://collections.library.yale.edu/catalog/12155857.