MLA

Green, L., and George E. Palade. Zymogen Granule Fraction Calf. Yale University School of Medicine, 2AD. https://collections.library.yale.edu/catalog/15817987.

APA, 6th edition

Green, L., & Palade, G. E. (2 C.E.). Zymogen granule fraction Calf [Transmission electron micrograph]. Yale University School of Medicine. https://collections.library.yale.edu/catalog/15817987.