MLA

Tar-Say. Pacer. Principal Apache Chief. William Soule, 0AD. https://collections.library.yale.edu/catalog/2010383.

APA, 6th edition

Tar-say. Pacer. Principal Apache Chief. (0 C.E.). [Photographic prints, Photographs, Studio portraits]. William Soule. https://collections.library.yale.edu/catalog/2010383.