MLA

Leoncavallo, Ruggiero, 1858-1919. Unidentified. Box 10, folder 308. 1895 Jan 24. https://collections.library.yale.edu/catalog/16666544.

APA, 6th edition

Leoncavallo, Ruggiero, 1858-1919. (["Box 10, folder 308"])(1895 Jan 24)[Unidentified]. https://collections.library.yale.edu/catalog/16666544.