1.题目：Measurement and explanation of socioeconomics inequality in health with longitudinal data
   作者：Jones, A.M., Lopez Nicolas, A.
   期刊：Health Economics, 2004, 13: 1015-1030.

2.题目：Income related inequalities in self assessed health in Britain:1979-2005
   作者：Gravelle H, Sutton M
   期刊：Journal of Epidemiology and Community health, 2003, 57:125-129.