Classification of journals in terms of bi-connected components
based on the citation matrix of the Journal Citation Report 2001
The methodology is explained in “Clusters and Maps of Science Journals Based on Bi-connected Graphs in the Journal Citation Reports,” Journal of Documentation, 60(4), (2004), 371-427; at http://www.leydesdorff.net/jcr01/art . <pdf-version>. See for analogous maps in the social sciences at http://www.leydesdorff.net/sosci01 (Scientometrics 60(2) (2004) 159-180).