1. Beauchamp, T.L., 2003. The nature of applied ethics. In: Frey, R.G. and Wellman, C.H. (eds.) A companion to applied ethics. Blackwell Publishers, Malden, MA, USA, pp. 1-16.
2. Beauchamp, T.L. and Childress, J.F., 2001. Principles of biomedical ethics. 5th edition. Oxford University Press, New York, NY, USA.
3. Brophy, B., 1972. In pursuit of a fantasy. In: Godlovitch, S., Godlovitch, R. and Harris, J. (eds.) Animals, men and morals: an inquiry into the maltreatment of non-humans. Grove Press, New York, NY, USA, pp. 124-125.