MLA

Speck, William A. (William Alfred), 1864-1928. 2 AL (copy, excerpt) : Weimar, to Karl Friedrich Graf von Reinhard. Box 9, folder 295. 1828 Jan 27. https://collections.library.yale.edu/catalog/2005325.

APA, 6th edition

Speck, William A. (William Alfred), 1864-1928. (["Box 9, folder 295"])(1828 Jan 27)[2 AL (copy, excerpt) : Weimar, to Karl Friedrich Graf von Reinhard]. https://collections.library.yale.edu/catalog/2005325.