"Beyonce And Jay Z Spotted At Vegan Restaurant Cafe Gratitude On His Birthday". “Oprah: Where Are They now?”, www.huffingtonpost.com. December 6, 2017.
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.97, BenBella Books