MLA

McClintock, Walter, 1870-1949. 227. [Evening View of the Grass-Covered Foothills. Yellow Bird Driving Horses.]. Box 61, folder 3056. 1938. https://collections.library.yale.edu/catalog/2008500.

APA, 6th edition

McClintock, Walter, 1870-1949. (["Box 61, folder 3056"])(1938)[227. [Evening View of the Grass-Covered Foothills. Yellow Bird Driving Horses.]]. https://collections.library.yale.edu/catalog/2008500.