From Thomson Reuters:
For the tenth consecutive year, ScienceWatch.com Webmaster Spyder Schafer presents the 10th annual “Top 20” listings of countries which, according to the latest bimonthly update of Essential Science Indicators, achieved particular distinction based on their papers published in Thomson Reuters-indexed journals from January 2001 through August 31, 2011, a 10-year plus 8-month period (fourth bimonthly).
Out of the 147 countries in the Essential Science Indicators database, 60 published at least 10,000 papers during the period. Countries are listed by three separate measures in the tables below: number of citations, total papers, and cites per paper. (Note: For articles with multiple authors representing different countries, each listed country receives full, not fractional, citation credit for the given paper.)
Three Lists are Available: