1. The nesting behaviour of sows and its disturbance by confinement at farrowing;Baxter,1982
2. Report of the Technical Committee to Enquire into the Welfare of Animals Kept under Intensive Livestock Husbandry Systems;Brambell,1965
3. Readings in Sociobiology;Clutton-Brock,1978
4. Can physiological criteria be used to assess welfare in pigs?;Dantzer,1981
5. Towards an objective method of assessing welfare in domestic fowl;Dawkins;Appl. Anim. Ethol.,1976