@article{DBLP:journals/tcs/Simpson93,
  author    = {Alex K. Simpson},
  title     = {A Characterisation of the Least-Fixed-Point Operator by
               Dinaturality},
  journal   = {Theor. Comput. Sci.},
  volume    = {118},
  number    = {2},
  year      = {1993},
  pages     = {301-314},
  ee        = {http://dx.doi.org/10.1016/0304-3975(93)90112-7},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}