MLA

Ernest Augustus, King of Hanover, 1771-1851. [Zauberflöte. Excerpts]. Arranged by Schäfer. Parts (4 ob, 2 cl, 2 bn, spt, 2 hn, 2 tpt (1 part)). Manuscript. Box 251, folder 1322-1324 | Box 252, folder 1325-1326. 1802?. https://collections.library.yale.edu/catalog/10000235.

APA, 6th edition

Ernest Augustus, King of Hanover, 1771-1851. (["Box 251, folder 1322-1324 | Box 252, folder 1325-1326"])(1802?)[[Zauberflöte. Excerpts]. Arranged by Schäfer. Parts (4 ob, 2 cl, 2 bn, spt, 2 hn, 2 tpt (1 part)). Manuscript]. https://collections.library.yale.edu/catalog/10000235.