MLA

Palade, George E. Heart Rat Ventricle. Yale University School of Medicine, 12AD. https://collections.library.yale.edu/catalog/15817900.

APA, 6th edition

Palade, G. E. (12 C.E.). Heart Rat ventricle [Transmission electron micrograph]. Yale University School of Medicine. https://collections.library.yale.edu/catalog/15817900.