1. Kenny A. Descartes’ philosophical letters. Oxford: Clarendon Press; 1970.
2. Harnad S. Other bodies, other minds: a machine incarnation of an old philosophical problem. Minds Mach. 1991;1(1):43–54.
3. Sneddon LU, Elwood RW, Adamo S, Leach MC. Defining and assessing pain in animals. Anim Behav. 2014;97:201–12.
4. Stamp Dawkins M. Why animals matter: animal consciousness, animal welfare, and human well-being. Oxford: Oxford University Press; 2012.
5. Griffin D. The question of animal awareness. New York: Rockefeller; 1976.