MLA

Clésinger-Sand, Solange, 1828-1899. Azmy, Wacyf. Box 1, folder 5-6. 1890-1899, undated. https://collections.library.yale.edu/catalog/17444445.

APA, 6th edition

Clésinger-Sand, Solange, 1828-1899. (["Box 1, folder 5-6"])(1890-1899, undated)[Azmy, Wacyf]. https://collections.library.yale.edu/catalog/17444445.