@article{KlinCMCS04,
  author    = {Bartek Klin},
  title     = {A Coalgebraic Approach to Process Equivalence and a Coinduction
               Principle for Traces},
  journal   = {Electr. Notes Theor. Comput. Sci.},
  volume    = {106},
  year      = {2004},
  pages     = {201-218},
  ee        = {http://dx.doi.org/10.1016/j.entcs.2004.02.029}
}