1. Spiegel EA, Wycis HT, Schor S, et al.: The incidence of vegetative symptoms in Parkinson patients with and without bradykinesia. In In Third Symposium on Parkinson Disease Royal College of Surgeons in Edinburgh. Edinburgh: E & S Livingston, Ltd; 1969:200.
2. Turkka J, Suominen K, Tolonen U, et al.: Selegiline diminishes cardiovascular autonomic responses in Parkinson’s disease. Neurology 1997, 48:662–667.
3. Martignoni E, Micieli G, Cavallini A, et al.: Autonomic disorders in idiopathic Parkinsonism. J Neural Transm 1986, 22:149–161.
4. Parkinson J: An essay on shaking palsy. London: Sherwood, Neely and Jones; 1817.
5. Gowers WR: A Manual of Diseases of the Nervous System, edn 2. London: Churchill; 1893:648.