MLA

Howe, Susan, 1937-. Dianthus / Pink / Sweet Alyssum. 74 (Broadside). early 1980s. https://collections.library.yale.edu/catalog/16852909.

APA, 6th edition

Howe, Susan, 1937-. (["74 (Broadside)"])(early 1980s)[Dianthus / Pink / Sweet Alyssum]. https://collections.library.yale.edu/catalog/16852909.