T. Colin Campbell, Thomas M. Campbell (II.) (2006). “The China Study: The Most Comprehensive Study of Nutrition Ever Conducted and the Startling Implications for Diet, Weight Loss and Long-term Health”, p.21, BenBella Books
"Animal Advocate and Author Karen Dawn: The Welfare of Animals and the Earth". Interview with Barbi Twins, www.marandapleasantmedia.com. January 27, 2015.