1. In America's Interest: Welcoming International Students;AIE, Association of International Educators,2003
2. Who gives foreign aid to whom and why?;Alesina;J. Econ. Growth,2000
3. Comparative Political Data Set I 1960–2011;Armingeon,2011
4. Cross-national Time-series Data Archive;Banks,2017
5. Correlates of War Project Trade Data Set Codebook;Barbieri,2012