@inproceedings{FichteSzeider11,
 author = {Johannes Klaus Fichte and Stefan Szeider},
 booktitle = {Proceedings of the 22nd International Joint Conference on 
Artificial Intelligence, IJCAI 2011},
 editor = {Toby Walsh},
 pages = {863-868},
 publisher = {AAAI Press/IJCAI},
 title = {Backdoors to Tractable Answer-Set Programming},
 year = {2011}
}