MLA

Cox, Christopher, 1949-1990. Video announcements and programs. Box 41, folder 634. 1985-1987. https://collections.library.yale.edu/catalog/10171433.

APA, 6th edition

Cox, Christopher, 1949-1990. (["Box 41, folder 634"])(1985-1987)[Video announcements and programs]. https://collections.library.yale.edu/catalog/10171433.