@article{BMS+09,
  author    = {M. Bauland and
               M. Mundhenk and
               T. Schneider and
               H. Schnoor and
               I. Schnoor and
               H. Vollmer},
  title     = {The Tractability of Model-checking for {LTL}: The Good, the
               Bad, and the Ugly Fragments},
  journal   = {Electr. Notes Theor. Comput. Sci.},
  volume    = 231,
  year      = {2009},
  pages     = {277-292},
  ee        = {http://dx.doi.org/10.1016/j.entcs.2009.02.041}
}