MLA

Marinetti, F. T., 1876-1944. Unidentified form completed by Marinetti with political past and professional accomplishments. [10721-1]. box 135, slide 21. no date. https://collections.library.yale.edu/catalog/10666947.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 135, slide 21"])(no date)[Unidentified form completed by Marinetti with political past and professional accomplishments. [10721-1]]. https://collections.library.yale.edu/catalog/10666947.