@inproceedings{dAFS04,
author =        {Luca de Alfaro and Marco Faella and 
                Marielle Stoelinga.},
booktitle =     {Proceedings 31st International Colloquium on
                Automata, Languages and Programming {(ICALP'04)},
title =         {Linear and Branching Metrics for Quantatative
                Transition Systems},
year =          2004,
series =        lncs,
volume =        3142,
pages =         97-109,
publisher =     {Springer--Verlag}
}