BMC Health Services Research, Volume 15, No. 1, Year 2015
PLoS ONE, Volume 7, No. 12, Year 2012
PLoS ONE, Volume 8, No. 10, Year 2013
PLoS ONE, Volume 8, No. 8, Year 2013
PLoS ONE, Volume 8, No. 4, Year 2013
BMC Pregnancy and Childbirth, Volume 10, Year 2010
Reproductive Health, Volume 7, No. 1, Year 2010