Comparison of methods for the detection of node group membership in bipartite networks E. N. Sawardecker, C. A. Amundsen, M. Sales-Pardo and L. A.N. Amaral Eur. Phys. J. B, 72 4 (2009) 671-677 Published online: 25 November 2009 DOI: 10.1140/epjb/e2009-00397-6