Cite

Pikes Peak above the clouds

MLA

Mellen, George Egbert. Pikes Peak above the Clouds. 0AD. https://collections.library.yale.edu/catalog/2014639.

APA, 6th edition

Mellen, G. E. (0 C.E.). Pikes Peak above the clouds [Card photographs, Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2014639.