(en) David Landis Barnhill et Roger S. Gottlieb, Deep Ecology and World Religions: New Essays on Sacred Ground, SUNY Press, (ISBN9780791491058, lire en ligne)
« ...tza'ar--literally "suffering" and understood to mean suffering that does not advance some legitimate human good... »
(en) Jacob Ari Labendz et Shmuly Yanklowitz, Jewish Veganism and Vegetarianism: Studies and New Directions, SUNY Press, (ISBN9781438473611, lire en ligne)
(en) Jacob Ari Labendz et Shmuly Yanklowitz, Jewish Veganism and Vegetarianism: Studies and New Directions, SUNY Press, , 320 p. (ISBN978-1-4384-7361-1, lire en ligne)
Adams & Sheridan, « specifying the risks to animal welfare associated with livestock slaughter without induced insensibility », Prepared as a Contribution from the Animal Welfare Branch, Product Integrity Animal and Plant Health Division, Australian Government Department of Agriculture, Fisheries and Forestry for the Animal Welfare Working Group of the Animal Health Committee, Primary Industries Standing Committee of Australia, , vii - 3. historical aspects (lire en ligne)