MLA

Marinetti, F. T., 1876-1944. Unsigned handwritten letter, dated 12/II/36, by Diulgheroff on Stile Futurista stationary. [7984-1]. box 101, slide 4. 1936. https://collections.library.yale.edu/catalog/10661675.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["box 101, slide 4"])(1936)[Unsigned handwritten letter, dated 12/II/36, by Diulgheroff on Stile Futurista stationary. [7984-1]]. https://collections.library.yale.edu/catalog/10661675.