Validation of a UPDRS-/MDS-UPDRS-based definition of functional dependency for Parkinson's disease
Ramsay, N., MacLeod, A. D., Alves, G., Camacho, M., Forsgren, L., Lawson, R. A., Maple-Grødem, J., Tysnes, O., Williams-Gray, C. H., Yarnall, A. J., Counsell, C. E., Parkinson’s Incidence Cohorts Collaboration
Parkinsonism & Related Disorders, vol. 76, pp. 49-53