MLA

Jackson, William Henry, 1843-1942, James, George Wharton, 1858-192. Great Dragon Rock, a study in erosion, 450 ft. from base of cliff to top of highest pinnacle, San Juan River, Utah. Folder 5B. [ca. 1890]. https://collections.library.yale.edu/catalog/2011322.

APA, 6th edition

Jackson, William Henry, 1843-1942, & James, George Wharton, 1858-192. (["Folder 5B"])([ca. 1890])[Great Dragon Rock, a study in erosion, 450 ft. from base of cliff to top of highest pinnacle, San Juan River, Utah]. https://collections.library.yale.edu/catalog/2011322.