MLA

Thomson, Virgil, 1896-1989. [Short fanfare] A short fanfare / Virgil Thomson.. Box 29A/31, folder 248. 1804-1990 (inclusive). https://collections.library.yale.edu/catalog/32266347.

APA, 6th edition

Thomson, Virgil, 1896-1989. (["Box 29A/31, folder 248"])(1804-1990 (inclusive))[[Short fanfare] A short fanfare / Virgil Thomson.]. https://collections.library.yale.edu/catalog/32266347.