1. Measuring health: a guide to rating scales and questionnaires;McDowell, I.; Newell, C.,1987
2. Quality of life: assessment and application;Walker, SR, Rosser; R.M.,1988
3. International classification of impairments, disabilities and handicaps;World Health Organisation,1980
4. Measuring handicap: motives, methods, and a model;Harwood, R.H.; Jitapunkul, S.; Dickinson, E.; Ebrahim, S.;Quality in Health Care,1994
5. Marketing research: methodological foundations;Churchill, G.A.,1989