The Lancet, Volume 388, No. 10053, Year 2016
BMC Medical Research Methodology, Volume 12, Year 2012
BMC Public Health, Volume 13, No. 1, Year 2013
The Lancet, Volume 388, No. 10053, Year 2016
BMC Public Health, Volume 12, No. 1, Year 2012
The Lancet, Volume 388, No. 10053, Year 2016