References
- Gulli, L. F., and T. Davidson. 2015. Parkinson’s disease. In The Gale encyclopedia of medicine, ed. by J. L. Longe 5th ed., 384–85. Farmington Hills, MI: Gale.
- National Institute of Neurological Disorders and Stroke (NINDS). 2015, September 30. Parkinson’s disease: Challenges, progress, and promise. NIH Publication No. 15–5595. http://www.ninds.nih.gov/disorders/parkinsons_disease/parkinsons_research.htm (accessed February 29, 2016).