MLA

Speck, William A. (William Alfred), 1864-1928. ALS : Jena, to Johann Wolfgang von Goethe. Box 3, folder 144. 1801 Nov 23. https://collections.library.yale.edu/catalog/16738551.

APA, 6th edition

Speck, William A. (William Alfred), 1864-1928. (["Box 3, folder 144"])(1801 Nov 23)[ALS : Jena, to Johann Wolfgang von Goethe]. https://collections.library.yale.edu/catalog/16738551.