<p>"The CWTS Leiden Ranking 2013 measures the scientific performance of 500 major universities worldwide. Using a sophisticated set of bibliometric indicators, the ranking aims to provide highly accurate measurements of the scientific impact of universities and of universities’ involvement in scientific collaboration. The CWTS Leiden Ranking 2013 is based on Web of Science indexed publications from the period 2008–2011. </p>
<p>Compared with other university rankings, the Leiden Ranking offers more advanced indicators of scientific impact and collaboration and uses a more transparent methodology. The Leiden Ranking does not rely on highly subjective data obtained from reputational surveys or on data provided by universities themselves. Also, the Leiden Ranking refrains from aggregating different dimensions of university performance into a single overall indicator. "</p>
<p><a href="http://www.leidenranking.com/ranking%5B/url%5D">http://www.leidenranking.com/ranking</a></p>