[Photograph of the Powell Memorial Monument]
MLA
Bros, Kolb. [Photograph of the Powell Memorial Monument]. 1921. https://collections.library.yale.edu/catalog/2018288.
APA, 6th edition
Bros, K. (1921). [Photograph of the Powell Memorial Monument] [Photographic prints, Photographs]. https://collections.library.yale.edu/catalog/2018288.