G. Gottlob, R. Pichler: "Hypergraphs in Model Checking: Acyclicity and Hypertree-Width versus Clique-Width"; SIAM JOURNAL ON COMPUTING, Volume 33 (2004), Number 2; 351 - 378.
http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04968385