@article{05493553,
title = {Contraction and treewidth lower bounds.},
journal = {Journal of Graph Algorithms and Applications},
volume = {10},
year = {2006},
pages = {5-49},
zbl = {1161.68644},
language = {en},
url = {http://dml.mathdoc.fr/item/05493553}
}
Bodlaender, Hans L.; Wolle, Thomas; Koster, Arie M.C.A. Contraction and treewidth lower bounds.. Journal of Graph Algorithms and Applications, Tome 10 (2006) pp. 5-49. http://gdmltest.u-ga.fr/item/05493553/