MLA

Gropius, Walter, 1883-1969, Moholy-Nagy, László, 1895-1946. Bauhausbücher 4. [1925]. https://collections.library.yale.edu/catalog/10268520.

APA, 6th edition

Gropius, Walter, 1883-1969, & Moholy-Nagy, László, 1895-1946. ([1925])[Bauhausbücher 4]. https://collections.library.yale.edu/catalog/10268520.