Wolfe Ingrid, Cass Hilary, Thompson Matthew J, Craft Alan, Peile Ed, Wiegersma Pieter A, Janson Staffan, Chambers T L, McKee Martin
London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK.
BMJ. 2011 Mar 8;342:d1277. doi: 10.1136/bmj.d1277.