Michael R. Fellows, Frances A. Rosamond, Udi Rotics, Stefan Szeider. Clique-width minimization is NP-hard. In Jon M. Kleinberg, editor, Proceedings of the 38th Annual ACM Symposium on Theory of Computing, Seattle, WA, USA, May 21-23, 2006. pages 354-362, ACM, 2006. [doi]
Abstract is missing.