1. Bradley, J. V. Distribution-free statistical tests. Englewood Cliffs: Prentice-Hall, 1968. Pp. 138–141.
2. Brown, J. S. Factors affecting self-punitive locomotor behavior. In B. A. Campbell, & R. M. Church (Eds.), Punishment and aversive behavior. New York: Appleton-Century-Crofts, 1969.
3. Brown, J. S., Martin, R. C., & Morrow, M. W. Self-punitive behavior in the rat: Facilitative effects of punishment on resistance to extinction. Journal of Comparative and Physiological Psychology, 1964, 57, 127–133.
4. Crowell, C. R., & Eaton, N. K. A fully automated two-way locomotor training apparatus. Behavior Research Methods & Instrumentation, 1974, 6, 19–22.
5. Fowler, H. Suppression and facilitation by response contingent shock. In F. R. Brush (Ed.), Aversive conditioning and learning. New York: Academic Press, 1971.