Grotle, Margreth, Philip Wilkens, Andrew M. Garratt, Inger Scheel, and Kjersti Storheim. 2013. “Which Roland-Morris Disability Questionnaire? Rasch Analysis of Four Different Versions Tested in a Norwegian Population”. Journal of Rehabilitation Medicine 45 (7):670-77. https://doi.org/10.2340/16501977-1166.