@article{HG05,
  author    =  {Hughes, D. J. D. and Glabbeek, R. J.~van},
  title     =  {Proof nets for unit-free multiplicative-additive linear logic},
  year      =  {2005},
  journal   =  {ACM Transactions on Computational Logic},
  note      =  {To appear. Invited submission November 2003, revised January 2005.
                Full version of the LICS'03 paper \cite{HG03}.
                Available at http://boole.stanford.edu/\,\~{ }dominic/papers}
}