1. Adams, R. D. and Martin, J. B. (1983). Pain. In Reterdorf, R. G., Adams, R. D., Braunwold, E., Isselbacher, K. J., Martin, J. B. and Wilson, J. D. (eds), Harrison’s Principles of Internal Medicine, 10th edn, McGraw-Hill, New York, pp. 7–15
2. Albe-Fessard, D., Condés-Lara, M., Sanderson, P. and Levante, A. (1984). Tentative explanation of the special role played by the areas of palcospinothalamic projection in patients with deafferentation pain syndromes, Adv. Pain Res. Ther., 6, 167–81
3. Alumets, J., Håkanson, R., Sundler, F. and Thorell, J. (1979). Neuronal localisation of immunoreactive enkephalin and β-endorphin in the earthworm, Nature, 279, 805–6
4. Amir, S., Brown, Z. W. and Amit, Z. (1980). The role of endorphins in stress: evidence and speculations, Neurosci. Biobehav. Rev., 4, 77–86
5. Amit, Z. and Galina, Z. H. (1986). Stress-induced analgesia: adaptive pain suppression, Physiol. Ref., 66, 1091–120