@proceedings{DBLP:conf/icalp/1991,
  editor    = {Javier Leach Albert and
               Burkhard Monien and
               Mario Rodr\'{\i}guez-Artalejo},
  title     = {Automata, Languages and Programming, 18th International
               Colloquium, ICALP91, Madrid, Spain, July 8-12, 1991, Proceedings},
  booktitle = {ICALP},
  publisher = {Springer},
  series    = {Lecture Notes in Computer Science},
  volume    = {510},
  year      = {1991},
  isbn      = {3-540-54233-7},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}