@inproceedings{JHB03,
 author    = {Markus Jakobsson and Jean-Pierre Hubaux and Levente Butty{\'a}n},
 title     = {}, Micro-Payment Scheme Encouraging Collaboration in Multi-hop Cellular Networks
 booktitle = {Financial Cryptography},
 year      = {2003},
 isbn      = {3-540-40663-8},
 pages     = {15--33},
 note      = {LNCS 2742},
 publisher = {Springer-Verlag},
 address   = {London, UK},
 }