Abstract
References
1.
McDowell I.
,
Newell C.
Measuring Health. A Guide to Rating Scales and Questionnaires, 2nd edn. Oxford : Oxford University Press , 1996
2.
Streiner D.L.
,
Norman GR.
Health Measurement Scales. A Practical Guide to their Development and Use, 2nd edn. Oxford : Oxford University Press , 1995