MLA

Marinetti, F. T., 1876-1944. Short texts by Pratella, Boccioni and some Futurists from Trapani. Salire. [04830-1]. box 61, slide 50. no date. https://collections.library.yale.edu/catalog/10656358.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 61, slide 50"])(no date)[Short texts by Pratella, Boccioni and some Futurists from Trapani. Salire. [04830-1]]. https://collections.library.yale.edu/catalog/10656358.