158.734 Y Young, Paul Thomas, 1892 Motivation of bihavior; the fundamental determinants of human and animal activity, by Paul Thomas Young… New York, J. Wilwy & sons, inc.; London, Chapman & Hall, limited, 1936. xviii, 502 p. ilus., diagrs. 23½ ´´Prepublication edition´´, 1933, has title: Motivation of human and animal behavior. ´´References´´ at end of each chapter.