1. On and off variability and response swings in Parkinson's disease. In eds. Research progress in Parkinson's disease. Kent, U. K.: Pitman Medical, 1981: 265-273.
2. World Health Organization. International classification on impairments, disability, and handicaps. Geneva: World Health Organization, 1980.
3. Scales for rating motor impairment in Parkinson's disease: studies of reliability and convergent validity.
4. and members of the UPDRS Development Committee. The Unified Parkinson's Disease Rating Scale. In eds. Recent developments in Parkinson's disease. Vol. 2. Florham Park, NJ: Macmillan Healthcare, 1987: 153-163.
5. Parkinsonism: onset, progression, and mortality