MLA

Berssenbrugge, Mei-mei, 1947-. Pollen notes. Box 19. 1966-1992, undated. https://collections.library.yale.edu/catalog/32238412.

APA, 6th edition

Berssenbrugge, Mei-mei, 1947-. (["Box 19"])(1966-1992, undated)[Pollen notes]. https://collections.library.yale.edu/catalog/32238412.