Hagger-Johnson Gareth E, Harron Katie, Goldstein Harvey, Parslow Roger, Dattani Nirupa, Borja Mario Cortina, Wijlaars Linda, Gilbert Ruth
Institute of Child Health/Department of Epidemiology and Public Health, University College London, London, UK.
BMJ. 2014 Mar 25;348:g2264. doi: 10.1136/bmj.g2264.