Cite

AL (copy), to Wilhelm von Humboldt

MLA

Speck, William A. (William Alfred), 1864-1928. AL (copy), to Wilhelm von Humboldt. Box 9, folder 281. 1831 Dec 1. https://collections.library.yale.edu/catalog/2005311.

APA, 6th edition

Speck, William A. (William Alfred), 1864-1928. (["Box 9, folder 281"])(1831 Dec 1)[AL (copy), to Wilhelm von Humboldt]. https://collections.library.yale.edu/catalog/2005311.