Roberts H R, Rushton L, Muir K R, Dengler R, Coupland C A, Jenkinson C M, Ruffell A, Chilvers C E
Department of Public Health Medicine and Epidemiology, University of Nottingham Medical School.
J Epidemiol Community Health. 1995 Aug;49(4):344-7. doi: 10.1136/jech.49.4.344.