MLA

Wulff, Lee, 1905-1991. Reports for Canadian government. Box 6. undated. https://collections.library.yale.edu/catalog/11700594.

APA, 6th edition

Wulff, Lee, 1905-1991. (["Box 6"])(undated)[Reports for Canadian government]. https://collections.library.yale.edu/catalog/11700594.