MLA

Ernest Augustus, King of Hanover, 1771-1851. [Symphony, no. 1, op. 21, C major]. Parts (2 vn, va, vc and b (2 copies), fl, 2 ob, 2 cl, 2 bn, spt, 2 hn, 2 tpt, trbn, timp). Manuscript. Box 188, folder 964-966. 1804?. https://collections.library.yale.edu/catalog/10000231.

APA, 6th edition

Ernest Augustus, King of Hanover, 1771-1851. (["Box 188, folder 964-966"])(1804?)[[Symphony, no. 1, op. 21, C major]. Parts (2 vn, va, vc and b (2 copies), fl, 2 ob, 2 cl, 2 bn, spt, 2 hn, 2 tpt, trbn, timp). Manuscript]. https://collections.library.yale.edu/catalog/10000231.