  The aggregated journal-journal citation matrix derived from the Journal
Citation Reports 2001 can be decomposed into a unique subject classification by
using the graph-analytical algorithm of bi-connected components. This technique
was recently incorporated in software tools for social network analysis. The
matrix can be assessed in terms of its decomposability using articulation
points which indicate overlap between the components. The articulation points
of this set did not exhibit a next-order network of 'general science' journals.
However, the clusters differ in size and in terms of the internal density of
their relations. A full classification of the journals is provided in an
Appendix. The clusters can also be extracted and mapped for the visualization.
