MLA

Barbour, George B. (George Brown), 1890-1977. Ming Tombs, Beijing, China, ca. 1920-1930. Box 19 | Folder 2. 1920-1930. https://collections.library.yale.edu/catalog/11420933.

APA, 6th edition

Barbour, George B. (George Brown), 1890-1977. (["Box 19 | Folder 2"])(1920-1930)[Ming Tombs, Beijing, China, ca. 1920-1930]. https://collections.library.yale.edu/catalog/11420933.