Difficulties in conducting a randomised controlled trial of health service interventions in intellectual disability : implications for evidence-based practice

Oliver, P.C., Piachaud, J., Done, D.J., Regan, A., Cooray, S. and Tyrer, P. (2002) Difficulties in conducting a randomised controlled trial of health service interventions in intellectual disability : implications for evidence-based practice. Journal of Intellectual Disability Research (4). pp. 340-345. ISSN 0964-2633