-  Batten Peter
Living Trophies
Crowell – New York 1976

- Brambell F.W.R. Chairman
Report of the techincal committee to enquire into the welfare of Animals kept under intensive livestock husbandry system.
Here Majesty’s Stazionery Office – London 1965.

- Dawkins Marian
Animal suffering: The science of Animal welfare.
Routledge, Chapman and Hall – New York 1980

- Druce Clare
Chicken and eggs: Who pays the price?
Merlin – London 1989

- Fox Michael
Farm Animals: Husbandry, behavior and Veterinary practive.
University Park Press – Baltimore 1984

- Godlovitch Stanley e Roslind
Animals, men and moral
Grove New York 1974

- Gold  Mark
Assault and battery
Pluto Press – London 1983