1. CEC, 1999. Council directive for laying down minimum standards for the protection of laying hens kept in various systems of rearing. CEC Directive,1999/74/EG.
2. Command Paper 2836, 1965. Report of the technical committee to enquire into the welfare of animals kept under intensive livestock husbandry systems. London: Her Majesty’s Stationery Office.
3. Priorities in the cage size and flooring preferences of domestic hens;Dawkins;Br. Poult. Sci.,1981
4. Cage height preference and use in battery-kept hens;Dawkins;Vet. Rec.,1985
5. Space needs of laying hens;Dawkins;Br. Poult. Sci.,1989