1. Alberta Dental Association and College, 2002. http://www.abda.ab.ca.
2. Back problems among dentists;Basset;Journal of the Canadian Dental Association,1983
3. Psychosocial factors at work and musculoskeletal disease;Bonger;Scandinavian Journal of Work, Environment and Health,1993
4. Research Methods in Occupational Epidemiology;Checkoway,1989
5. Maximizing response fate and controlling non-response error in survey research;Diem,2002