USAID:10.1377/hlthaff.28.6.1745
USAID:10.1377/hlthaff.2009.0782
USAID:10.1377/hlthaff.2012.0193
USAID:10.1377/hlthaff.2012.0227
USAID:10.1377/hlthaff.2012.0562
USAID:10.1377/hlthaff.2015.0902
USAID:10.1377/hlthaff.2015.1418