@inproceedings{isc06,
  author = {Jonker, H.L. and Vink, E. de},
  title = {Formalising Receipt-Freeness},
  booktitle = {Proc.\ ISC 2006},
  editor = {S.K. Katsikas and J. Lopez and M. Backes and S. Gritzalis 
    and B. Preneel},
  publisher = {LNCS 4176},
  pages = {476--488},
  year = {2006}
}