Rogers S, Humphrey C, Nazareth I, Lister S, Tomlin Z, Haines A
Department of Primary Care and Population Sciences, Royal Free and University College Medical School, University College London, Archway Resource Centre, London N10 3UA.
BMJ. 2000 Jun 10;320(7249):1580-3. doi: 10.1136/bmj.320.7249.1580.