Hull, C.L. (1920). Quantitative aspects of the evolution of concepts. Psychological Monographs, 38, No. 123.) Hull, C. L. (1924). The influence of tobacco smoking on mental and motor efficiency. Psychological monographs, 33, No. 3, 1-160. Hull, C. L. (1925). An automatic correlation calculating machine. Journal of American Statistical Association, 20, 522–531 Hull, C. L. (1928). Aptitude testing. Yonkers, New York: World, 1928. Hull, C. L. (1933). Hypnosis and suggestibility. An experimental approach. New York: Appleton-Century. Hull, C. L. (1943). Principles of behavior. New York: Appleton-Century-Crofts. Hull, C. L. (1951). Essentials of behavior. New Haven, Connecticut: Yale University Press. Hull, C. L. (1952). A behavior system. New Haven, Connecticut: Yale University Press. Hull, C. L., Ross, R. T., Hall, M., Perkins, D. T., & Fitch, F. G. (1940). Mathematico-Deductive Theory of Rote Learning. New Haven, Connecticut: Yale University press.