1. 题目: The impact of migration on rural poverty and inequality: a case study in China
   作者：Nong Zhu and Xubei Luo
   期刊：Agricultural economics, vol 41, issues 2, pages 191-204.
   
2. 题目：EDUCATION AND INCOME INEQUALITY IN THE REGIONS OF THE EUROPEAN UNION
   作者：Andres Rodriguez and Vassilis Tselios
   期刊：Journal of regional science, vol 49, issue 3, pages 411-437, 2009

3. 题目：Income Mobility in the United States: New Evidence from Income Tax Data
   作者：Auten Gerald and Gee Geoffrey
   期刊：National tax Journal, vol 62, issue 2, pages 301-328. 2009