MLA

Steinberg, Saul, 1914-1999. Photographs of Sigrid Spaeth. Box 148, folder 2780 | Box 299, folder 4498. 1960-1995, undated. https://collections.library.yale.edu/catalog/10190007.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 148, folder 2780 | Box 299, folder 4498"])(1960-1995, undated)[Photographs of Sigrid Spaeth]. https://collections.library.yale.edu/catalog/10190007.