MLA

Marinetti, F. T., 1876-1944. Autograph manuscript notes and drawing written on envelope and letter to FTM from a friend (signed "Tua") dated [1916] Dec 10. 6 p., 4 pages on letter plus 2 pages of notes on envelope. Box 40, folder 1706. 1895-1944. https://collections.library.yale.edu/catalog/16687052.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["Box 40, folder 1706"])(1895-1944)[Autograph manuscript notes and drawing written on envelope and letter to FTM from a friend (signed "Tua") dated [1916] Dec 10. 6 p., 4 pages on letter plus 2 pages of notes on envelope]. https://collections.library.yale.edu/catalog/16687052.