MLA

Trudeau, G. B., 1948-. Doonesbury. Box 1979. 1979 September 14. https://collections.library.yale.edu/catalog/2052822.

APA, 6th edition

Trudeau, G. B., 1948-. (["Box 1979"])(1979 September 14)[Doonesbury]. https://collections.library.yale.edu/catalog/2052822.