MLA

Plowden, David (1932). The Hell Gate Bridge, East River, Gustav Lindenthal, Engineer. New York, New York (GFB-469-252). Box 50. 1969 April. https://collections.library.yale.edu/catalog/2041113.

APA, 6th edition

Plowden, David (1932). (["Box 50"])(1969 April)[The Hell Gate Bridge, East River, Gustav Lindenthal, Engineer. New York, New York (GFB-469-252)]. https://collections.library.yale.edu/catalog/2041113.