@article{cliquewidthanddirectedwidthmeasuresfor,
  title = {Clique-Width and Directed Width Measures for Answer-Set Programming},
  author = {Bernhard Bliem and Sebastian Ordyniak and Stefan Woltran},
  year = {2016},
  eprint = {1606.09449},
  archivePrefix = {arXiv},
  url = {http://arxiv.org/abs/1606.09449v2},
}