@Inproceedings{EPTCS9.5,
  author    = {Dezani-Ciancaglini, Mariangiola  and Giannini, Paola  and Troina, Angelo },
  year      = {2009},
  title     = {A Type System for Required/Excluded Elements in CLS},
  editor    = {Cooper, S. Barry and Danos, Vincent},
  booktitle = {{\rm Proceedings Fifth Workshop on Developments in Computational Models ---}
               Computational Models From Nature,
               {\rm Rhodes, Greece, 11th  July 2009}},
  series    = {Electronic Proceedings in Theoretical Computer Science},
  volume    = {9},
  publisher = {Open Publishing Association},
  pages     = {38-48},
  doi       = {10.4204/EPTCS.9.5},
}