Zwakhalen, Sandra M.G., Koopmans, Raymond T.C.M., Geels, Paul J.E.M., Berger, Martijn P.F. and Hamers, Jan P.H. (2008) The prevalence of pain in nursing home residents with dementia measured using an observational pain scale. European Journal of Pain, 13 (1). pp. 89-93. ISSN 1090-3801 (doi:https://doi.org/10.1016/j.ejpain.2008.02.009)