@article{GRS14-ECA
   year={2014},
   issn={0925-9856},
   journal={Formal Methods in System Design},
   doi={10.1007/s10703-014-0212-1},
   title={On regions and zones for event-clock automata},
   url={http://dx.doi.org/10.1007/s10703-014-0212-1},
   publisher={Springer US},
   author={Geeraerts, Gilles and Raskin, Jean-Fran\c cois and Sznajder, Nathalie},
   pages={1-51}
}