Michael R. Fellows, Fedor V. Fomin, Daniel Lokshtanov, Frances A. Rosamond, Saket Saurabh, Stefan Szeider, Carsten Thomassen. On the Complexity of Some Colorful Problems Parameterized by Treewidth. Proceedings of COCOA 2007, Combinatorial Optimization and Applications, First International Conference, Xi’an, China, August 14-16, 2007, volume 4616 of Lecture Notes in Computer Science, pages 366-377, 2007, Springer Verlag.