APA-referens (7:e uppl.)

Widder, R. B. (1966). A Pictorial treasury of the smithsonian institution. Chilton.

Chicago-referens (17:e uppl.)

Widder, Robert B. A Pictorial Treasury of the Smithsonian Institution. Philadelphia: Chilton, 1966.

MLA-referens (9:e uppl.)

Widder, Robert B. A Pictorial Treasury of the Smithsonian Institution. Chilton, 1966.