MLA

Simpson, Randolph Linsly, 1927-1992. Color by H.F. Gardner "James Baldwin" Three quarter length of Baldwin in suit standing in auditorium. Postcard in color. Box 25, folder 1036. circa 1960. https://collections.library.yale.edu/catalog/32312520.

APA, 6th edition

Simpson, Randolph Linsly, 1927-1992. (["Box 25, folder 1036"])(circa 1960)[Color by H.F. Gardner "James Baldwin" Three quarter length of Baldwin in suit standing in auditorium. Postcard in color]. https://collections.library.yale.edu/catalog/32312520.