MLA

Marinetti, F. T., 1876-1944. Unidentified page of a periodical containing: Sacchi: “Liberamoci!!!” [1109-1]. box 15, slide 9. no date. https://collections.library.yale.edu/catalog/10650138.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 15, slide 9"])(no date)[Unidentified page of a periodical containing: Sacchi: “Liberamoci!!!” [1109-1]]. https://collections.library.yale.edu/catalog/10650138.