MLA

Trudeau, G. B., 1948-. Daily pencils. Box 160. [1999?]. https://collections.library.yale.edu/catalog/2053561.

APA, 6th edition

Trudeau, G. B., 1948-. (["Box 160"])([1999?])[Daily pencils]. https://collections.library.yale.edu/catalog/2053561.