MLA

Wolf-Ferrari, Ermanno, 1876-1948. "Serenata". Box 18 (Oversize), folder Oversize 88. undated. https://collections.library.yale.edu/catalog/17353499.

APA, 6th edition

Wolf-Ferrari, Ermanno, 1876-1948. (["Box 18 (Oversize), folder Oversize 88"])(undated)["Serenata"]. https://collections.library.yale.edu/catalog/17353499.