@conference{JP06a,
  title = "Towards a quantum calculus",
  author = "Ph. Jorrand, S. Perdrix",
  year = "2006",
  booktitle = "Proceedings of the 4th International Workshop on Quantum Programming Languages, ENTCS (to appear)",
  url = "http://www.mathstat.dal.ca/~selinger/qpl2006/PDFS/06-Jorrand-Perdrix.pdf",
}