MLA

Steinberg, Saul, 1914-1999. Palazzo Strozzi. Box 420, folder 5674. 1981. https://collections.library.yale.edu/catalog/16849964.

APA, 6th edition

Steinberg, Saul, 1914-1999. (["Box 420, folder 5674"])(1981)[Palazzo Strozzi]. https://collections.library.yale.edu/catalog/16849964.