MLA

White, Walter, 1893-1955. Jackson, Mabel Dodge. Box 10, folder 52. 1949-1955. https://collections.library.yale.edu/catalog/17024137.

APA, 6th edition

White, Walter, 1893-1955. (["Box 10, folder 52"])(1949-1955)[Jackson, Mabel Dodge]. https://collections.library.yale.edu/catalog/17024137.