MLA

Geographical Surveys West of the 100th Meridian (U.S.). Photographs of Geographical Explorations and Surveys West of the 100th Meridian. 2 vols.. Box 46 | Box 47. ca. 1873. https://collections.library.yale.edu/catalog/2003066.

APA, 6th edition

Geographical Surveys West of the 100th Meridian (U.S.). (["Box 46 | Box 47"])(ca. 1873)[Photographs of Geographical Explorations and Surveys West of the 100th Meridian. 2 vols.]. https://collections.library.yale.edu/catalog/2003066.