1. Davis, W. M., Huneycutt, B. D., Babbini, M.: A new apparatus for one-way locomotor avoidance without handling. Psychon. Sci. 8, 185?186 (1967)
2. Davis, W. M., Babbini, M., Khalsa, J. H.: Antagonism by alpha-methyltyrosine of morphine induced motility in non-tolerant and tolerant rats. Res. Commun. chem. Path. Pharmacol. 4, 267?279 (1972)
3. Davis, W. M., Holbrook, J. M., Babbini, M.: Differential effects of morphine on active avoidance as a function of pre-drug performance. Pharmacol. Res. Commun. 5, 47?53 (1973)
4. Duncan, D. B.: Multiple range and multiple F tests. Biometrics 11, 1?41 (1955)
5. Hill, H. E., Bell, E. C., Wikler, A.: Reduction of conditioned suppression: Actions of morphine compared with those of amphetamine, pentobarbital, nalorphine, cocaine, LSD-25 and chlorpromazine. Arch. int. Pharmacodyn. 165, 212?225 (1967)