MLA

Conrad, Joseph, 1857-1924. Suspense. Box 21. circa 1923-1924. https://collections.library.yale.edu/catalog/2041560.

APA, 6th edition

Conrad, Joseph, 1857-1924. (["Box 21"])(circa 1923-1924)[Suspense]. https://collections.library.yale.edu/catalog/2041560.