MLA

Van Vechten, Carl, 1880-1964. Bouvier, Leni, as Hélène, and Eugene van Grona as Paris in La belle Hélène choreographed by Eugene van Grona. Box 337, folder 4276. 1938 March 9. https://collections.library.yale.edu/catalog/10563875.

APA, 6th edition

Van Vechten, Carl, 1880-1964. (["Box 337, folder 4276"])(1938 March 9)[Bouvier, Leni, as Hélène, and Eugene van Grona as Paris in La belle Hélène choreographed by Eugene van Grona]. https://collections.library.yale.edu/catalog/10563875.