Ryder, R. D., & Singer, P. (2015). Speciesism, painism and happiness: A morality for the twenty-first century. Imprint Academic.

Ryder, Richard D., and Peter Singer. Speciesism, Painism and Happiness: A Morality for the Twenty-first Century. Exeter, England: Imprint Academic, 2015.

Ryder, Richard D., and Peter Singer. Speciesism, Painism and Happiness: A Morality for the Twenty-first Century. Imprint Academic, 2015.