MLA

Marinetti, F. T., 1876-1944. Elpidio Piccoli. No title. No source. Quotes “(Sonetto) A Cernagora e Serbia” and “Prole Eroica.” [2354-1]. box 30, slide 54. no date. https://collections.library.yale.edu/catalog/10652000.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 30, slide 54"])(no date)[Elpidio Piccoli. No title. No source. Quotes “(Sonetto) A Cernagora e Serbia” and “Prole Eroica.” [2354-1]]. https://collections.library.yale.edu/catalog/10652000.