MLA

National Geographic Society (U.S.). Cartographic Section. The southwestern United States / executed in the Cartographic Section of the National geographic magazine ; James M. Darley, chief cartographer ; culture by Apphia E. Holdstock ; research by Wellman Chamberlin ; physiography by John J. Brehm and H.E. East. BRBL_00506. 1940. https://collections.library.yale.edu/catalog/15811218.

APA, 6th edition

National Geographic Society (U.S.). Cartographic Section. (["BRBL_00506"])(1940)[The southwestern United States / executed in the Cartographic Section of the National geographic magazine ; James M. Darley, chief cartographer ; culture by Apphia E. Holdstock ; research by Wellman Chamberlin ; physiography by John J. Brehm and H.E. East]. https://collections.library.yale.edu/catalog/15811218.