1. Blue, L . Do red heads really feel more pain? The jury’s still out. Time. August 12, 2009. Accessed: October 20, 2010.
2. Cass, C . The Red Head Handbook. Blue Mountain Arts, Inc., 2003.
3. Douglas, S . The Redhead Encyclopedia. Redheads International/Stone Castle Literary Group, 1996.
4. Genetic determinants of hair color and parkinson's disease risk
5. Garreau, J . Red Alert! The Washington Post. March 19, 2002. Accessed: October 23, 2010.