Pickering, Alan; Corr, Philip J; Powell, Jane H; Kumari, Veena; Thornton, Jasper C and Gray, Jeffrey A. 1997. Individual differences in reactions to reinforcing stimuli are neither black nor white: To what extent are they Gray? In: Helmuth Nyborg, ed. The scientific study of human nature : tribute to Hans J. Eysenck at eighty. Oxford; New York: Elsevier Science, pp. 36-67. ISBN 9780585474496 [Book Section]