MLA

Marinetti, F. T., 1876-1944. 340. Belgrade. FTM and five unidentified men. Inscribed on verso in FTM's hand: "Nella Direzione di Vreme? a Belgrado.". Box 51, folder 1960. n.d.. https://collections.library.yale.edu/catalog/2009167.

APA, 6th edition

Marinetti, F. T., 1876-1944. (["Box 51, folder 1960"])(n.d.)[340. Belgrade. FTM and five unidentified men. Inscribed on verso in FTM's hand: "Nella Direzione di Vreme? a Belgrado."]. https://collections.library.yale.edu/catalog/2009167.