Jillian Michaels, Mariska van Aalst (2009). “Master Your Metabolism: The 3 Diet Secrets to Naturally Balancing Your Hormones for a Hot and Healthy Body!”, p.21, Harmony
"'The Economy Fell off the Cliff'". Interview with Mathias Müller von Blumencron, Gregor Peter Schmitz and Gabor Steingart, www.spiegel.de. November 24, 2008.