1. Academic Ranking of World Universities Ranking methodology http://www.arwu.org/ARWUSubjectMethodology2010.jsp
2. Central Intelligence Agency The world factbook: Appendix B: International organizations and groups https://www.cia.gov/library/publications/the-world-factbook/appendix/appendix-b.html#N
3. CME Group Index Services 2010 Dow Jones total stock market indexes http://www.djindexes.com/mdsidx/downloads/brochure_info/Dow_Jones_Total_Stock_Market_Indexes_Brochure.pdf
4. Methods for accrediting publications to authors or countries: Consequences for evaluation studies;Egghe;Journal of the American Society for Information Science,2000
5. Counting methods are decisive for rankings based on publications and citation studies;Gauffriau;Scientometrics,2005