Cite

Buffalo Bill : yours truly, W.F. Cody "Buffalo Bill".

MLA

Buffalo Bill : Yours Truly, W.F. Cody "Buffalo Bill". A. Gast & Co. lith, 0AD. https://collections.library.yale.edu/catalog/2001501.

APA, 6th edition

Buffalo Bill : yours truly, W.F. Cody "Buffalo Bill". (0 C.E.). [Portraits, Lithographs]. A. Gast & Co. lith. https://collections.library.yale.edu/catalog/2001501.