MLA

Marinetti, F. T., 1876-1944. [Filippo Tomasso Marinetti?]. “Futurismus und Passeismus.” Neue Freie Press, 25 Aug 1921. In German. [2606-1]. box 33, slide 66. 1921. https://collections.library.yale.edu/catalog/10652537.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 33, slide 66"])(1921)[[Filippo Tomasso Marinetti?]. “Futurismus und Passeismus.” Neue Freie Press, 25 Aug 1921. In German. [2606-1]]. https://collections.library.yale.edu/catalog/10652537.