G. Gottlob, R. Pichler, F. Wei:
"Monadic Datalog over Finite Structures with Bounded Treewidth";
Talk: PODS 2007, Beijing, China; 2007-06-11 - 2007-06-13; in: "Proceedings of the Twenty-Sixth ACM SIGMOD-SIGACT-SIGART -Symposium on Principles of Database Systems (PODS 2007)", P. Kolaitis (ed.); ACM, (2007), ISBN: 978-1-59593-685-1; 165 - 174.