1. de Groot CPGM van Staveren WA. Nutrition and the elderly. A European collaborative study in cooperation with the World Health Organization (WHO-SPRA) and the International Union of Nutritional Sciences (IUNS), Committee on Geriatric Nutrition. Manual of operations. Euronut report 11, Wageningen, the Netherlands, 1988
2. Euronut SENECA study on nutrition and the elderly. Design, methods and participation;Hof;Eur J Clin Nutr,1991
3. Rasmussen NK. Nordiske Helbreds- & Sygelighed-sundersøgelser Nordisk Ministerråd. ISBN 87-503-5152-4, 1984
4. A physical activity questionnaire for the elderly;Voorrips;Med Sci Sports Exerc,1991