MLA

McClintock, Walter, 1870-1949. G5x7-85. Sunset and Lake. Cloud Bank Over Rockies. Lake Reflections and Long Grass. Box 125, folder 5805. undated. https://collections.library.yale.edu/catalog/10453578.

APA, 6th edition

McClintock, Walter, 1870-1949. (["Box 125, folder 5805"])(undated)[G5x7-85. Sunset and Lake. Cloud Bank Over Rockies. Lake Reflections and Long Grass]. https://collections.library.yale.edu/catalog/10453578.