MLA

Speck, William A. (William Alfred), 1864-1928. Schillers Haus. Box 17. circa 1750-1850. https://collections.library.yale.edu/catalog/2013148.

APA, 6th edition

Speck, William A. (William Alfred), 1864-1928. (["Box 17"])(circa 1750-1850)[Schillers Haus]. https://collections.library.yale.edu/catalog/2013148.