Black and white photograph of infant crawling on visual cliff checker board
in Richard D. Walk Papers, of University of Akron. Cummings Center for the History of Psychology; with Richard David Walk, 1920-1999, Series Four: Research Files, 1945-1997. Subseries One: Visual Cliff Research, 1958-1996, Box M4960, Folder 6: Visual cliff - babies photos, undated , 1 page(s)