Zdroj: Mad Cowboy (1998), Ch. 9: Going Home, p. 188
Howard Lyman: Citáty anglicky
Zdroj: No More Bull! (2005), Ch. 5: Message for My Meat-Eating Friends, p. 61
But you probably will feel more energy, and enjoy a longer and healthier life.
Zdroj: Mad Cowboy (1998), Ch. 2: The Simple Facts, pp. 40-41
Zdroj: Mad Cowboy (1998), Ch. 7: Bovine Planet, p. 149
Zdroj: Mad Cowboy (1998), Ch. 4: From the Farm to the Capital, pp. 80-81
Zdroj: Mad Cowboy (1998), Ch. 4: From the Farm to the Capital, p. 81
Zdroj: No More Bull! (2005), Ch. 5: Message for My Meat-Eating Friends, p. 78
Zdroj: No More Bull! (2005), Ch. 6: Message for My Fellow Vegetarians and Vegans, pp. 79-80
Zdroj: No More Bull! (2005), Ch. 4: Alzheifer's Disease?, p. 56
Interview in the documentary-film Cowspiracy by Kip Andersen and Keegan Kuhn (2014).