HennessyM85'

@article{DBLP:journals/jacm/HennessyM85,
  author    = {Matthew Hennessy and
               Robin Milner},
  title     = {Algebraic Laws for Nondeterminism and Concurrency},
  journal   = {J. ACM},
  volume    = {32},
  number    = {1},
  year      = {1985},
  pages     = {137-161},
  ee        = {http://doi.acm.org/10.1145/2455.2460},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}