MLA

Stettheimer, Florine, 1871-1944. O'Keeffe, Georgia. Box 3, folder 61-63. 1927-54. https://collections.library.yale.edu/catalog/16721914.

APA, 6th edition

Stettheimer, Florine, 1871-1944. (["Box 3, folder 61-63"])(1927-54)[O'Keeffe, Georgia]. https://collections.library.yale.edu/catalog/16721914.