@Inproceedings{EPTCS1.5,
  author    = {De Mol, Liesbeth},
  year      = {2009},
  title     = {On the boundaries of solvability and unsolvability in tag systems. Theoretical and Experimental Results.},
  editor    = {Neary, Turlough and Woods, Damien and Seda, Tony and Murphy, Niall},
  booktitle = {{\rm Proceedings International Workshop on}
               The Complexity of Simple Programs,
               {\rm Cork, Ireland, 6-7th December 2008}},
  series    = {Electronic Proceedings in Theoretical Computer Science},
  volume    = {1},
  publisher = {Open Publishing Association},
  pages     = {56-66},
  doi       = {10.4204/EPTCS.1.5},
}