MLA

Wilder, Thornton, 1897-1975. Life portraits and group portrait of participants in Goethe Festival, including Albert Schweitzer, Aspen. Box 150, folder 3608. 1949 Aug. https://collections.library.yale.edu/catalog/2037302.

APA, 6th edition

Wilder, Thornton, 1897-1975. (["Box 150, folder 3608"])(1949 Aug)[Life portraits and group portrait of participants in Goethe Festival, including Albert Schweitzer, Aspen]. https://collections.library.yale.edu/catalog/2037302.