1. Symbolic, historical, and cultural aspects of animal euthanasia;Langner,1988
2. Animal rights and human morality;Rollin,1992
3. Blue juice;Morris,2012
4. The last walk;Pierce,2012
5. Ancient euthanasia: ‘good death’ and the doctor in the Graeco-Roman World;Van Hooff;Soc Sci Med,2004