MLA

Hayward & Muzzall, Hayward, E. J., b. 1838. Blooded stock, San Julian Ranch. Box 19 | Folder : Hayward & Muzzall. undated. https://collections.library.yale.edu/catalog/10466830.

APA, 6th edition

Hayward & Muzzall, & Hayward, E. J., b. 1838. (["Box 19 | Folder : Hayward & Muzzall"])(undated)[Blooded stock, San Julian Ranch]. https://collections.library.yale.edu/catalog/10466830.