MLA

Faber du Faur, Curt von, 1890-1966. Bircher, Martin. Box 19, folder 152. 1960-1961. https://collections.library.yale.edu/catalog/17271158.

APA, 6th edition

Faber du Faur, Curt von, 1890-1966. (["Box 19, folder 152"])(1960-1961)[Bircher, Martin]. https://collections.library.yale.edu/catalog/17271158.