MLA

Marinetti, F. T., 1876-1944. Proof of the French version. With corrections Unpublished. 99 p., numbered 21-119.. Box 40, folder 1702. 1895-1944. https://collections.library.yale.edu/catalog/16687051.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["Box 40, folder 1702"])(1895-1944)[Proof of the French version. With corrections Unpublished. 99 p., numbered 21-119.]. https://collections.library.yale.edu/catalog/16687051.