7Eisdorfer C, Cohen D, Paveza GJ, et al. An empirical evaluation of the Global Deterioration Scale for staging Alzheimer's disease.Am J Psychiatry 1992;149(2):190-4.
8Otero A, Zunzunegui MV, Rodriguez-Laso A, et al. Burden and trends of activities of daily living disability in elderly Spanish people.Rev Esp Salud Publica2004;78(2):201-13.