@InProceedings{Obd06,
  author = 	 {J. Obdr\v{z}\'alek},
  title = 	 {{D}{A}{G}-width -- Connectivity Measure for Directed Graphs},
  booktitle = 	 {Symposium on Discrete Algorithms},
  pages =	 {814--821},
  year =	 2006,
  publisher =	 {ACM-SIAM}
}