1. Adams, W. J., Yeh, S. Y., Woods, L. A., Mitchell, C. L.: Drug-test interaction as a factor in the development of tolerance to the analgesic effect of morphine. J. Pharmacol. exp. Ther. 168, 251?257 (1969).
2. Ferguson, R. K., Mitchell, C. L.: Pain as a factor in the development of tolerance to morphine analgesia in man. Clin. Pharmacol. Ther. 10, 372?382 (1969).
3. Gebhart, G. F., Mitchell, C. L.: Further studies on the development of tolerance to the analgesic effect of morphine: the role played by the cylinder in the hot plate testing procedure. Arch. int. Pharmacodyn. 191, 96?103 (1971a).
4. - - The relative contributions to the development of tolerance to the analgesic effect of morphine made by the testing cylinder and the plate in the hot plate procedure. Europ. J. Pharmacol. Submitted (1971 b).
5. - Sherman, A. D., Mitchell, C. L.: The influence of stress on tolerance development to morphine in rats tested on the hot plate. Arch. int. Pharmacodyn. Submitted (1971).