MLA

Dreier, Katherine S. (Katherine Sophie), 1877-1952. Dreier, Dorothea A. Journal regarding trip to Europe with KSD and Mary Quinn, holograph, volume (in Series VI). Box 127, folder 2871. 1902-03. https://collections.library.yale.edu/catalog/32210005.

APA, 6th edition

Dreier, Katherine S. (Katherine Sophie), 1877-1952. (["Box 127, folder 2871"])(1902-03)[Dreier, Dorothea A. Journal regarding trip to Europe with KSD and Mary Quinn, holograph, volume (in Series VI)]. https://collections.library.yale.edu/catalog/32210005.