of the most recent 10 years were cited by individual specific journals during the year (the twenty journals with the greatest number of citations are given)
* and several measures derived from these data for a given journal: its impact factor, immediacy index, etc.

There are separate editions for the sciences and the social sciences; the 2013 science edition includes 8,411 journals, and the 2012 social science edition contains 3,016 titles. The issue