MLA

Van Vechten, Carl, 1880-1964. Laing, Hugh, as Benno, in Swan Lake, ballet choreographed by Anton Dolin after Marius Petipa. Box 358, folder 4911. 1940 July 19. https://collections.library.yale.edu/catalog/2055757.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 358, folder 4911"])(1940 July 19)[Laing, Hugh, as Benno, in Swan Lake, ballet choreographed by Anton Dolin after Marius Petipa]. https://collections.library.yale.edu/catalog/2055757.