The Web of Science has recently introduced a new citation analysis metric Hirsh's h-index. The h-index index measures the number of papers with citation numbers higher or equal to h. H-index can be accessed by selecting "Citation Report" from a Web of Science search results list.

Hirsch, JE 2005 “An index to quantify an individual’s scientific research output”, Proceedings of the National Academy of Sciences of the United States of America, vol. 102, no. 46, pp16569-16572.