MLA

Clésinger-Sand, Solange, 1828-1899. Aubineaux, L.. Box 1, folder 2. 1876 November 6. https://collections.library.yale.edu/catalog/17444442.

APA, 6th edition

Clésinger-Sand, Solange, 1828-1899. (["Box 1, folder 2"])(1876 November 6)[Aubineaux, L.]. https://collections.library.yale.edu/catalog/17444442.