Stevens, Harvey A., Mental retardation; : a review of research, [electronic resource] / edited by Harvey A. Stevens and Rick Heber.. — Chicago, : University of Chicago Press, [1964]. — xii, 502 p. : illus. 24 cm. Includes bibliographies. LCCN: 64015808 //r84 Subjects--Topical Terms: Mental retardation. LC Class. No.: RC570 / .S7 Dewey Class. No.: 132.2