Olson, David R. Cognitive development the child's acquisition of diagonality [by] David R. Olson. - New York Academic Press 1970. - xvi, 220 p. illus. 24 cm. - The Child psychology series . Bibliography: p. 204-209. ISBN: 0125256507 LCCN: 72127694 Subjects--Topical Terms: Cognition in children LC Class. No.: BF723.C5 / O45 Dewey Class. No.: 155.41/3