NiehrenP03'

@article{DBLP:journals/iandc/NiehrenP03,
  author    = {Joachim Niehren and
               Tim Priesnitz},
  title     = {Non-structural subtype entailment in automata theory},
  journal   = {Inf. Comput.},
  volume    = {186},
  number    = {2},
  year      = {2003},
  pages     = {319-354},
  ee        = {http://dx.doi.org/10.1016/S0890-5401(03)00140-8},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}