1. Report on the Colloquium on Recognition and Alleviation of Animal Pain and Distress;American Veterinary Medical Association Panel,1987
2. The detection and relief of pain in animals;British Veterinary Association Animal Welfare Symposium,1985
3. Recognition and alleviation of pain in animals;Flecknell,1986
4. Processes of ethological hemeostasis;Fraser;Appl. Anim. Ethol.,1983