MLA

Nicholls, Norton, 1741?-1809. Duchess di Castelpagano to Norton Nicholls. Naples. Concerns Italy; Wurmbrand. Box 2, folder 174. 1772 Sep 30. https://collections.library.yale.edu/catalog/17439971.

APA, 6th edition

Nicholls, Norton, 1741?-1809. (["Box 2, folder 174"])(1772 Sep 30)[Duchess di Castelpagano to Norton Nicholls. Naples. Concerns Italy; Wurmbrand]. https://collections.library.yale.edu/catalog/17439971.