@inproceedings {PJCS-96c, title = {On Approximate Performance Evaluation of Manufacturing Systems Modelled with Weighted T Systems}, year = {1996}, month = {7}, pages = {201-207}, url = {http://webdiis.unizar.es/CRPetri/papers/jcampos/96_PJCS_c.ps.gz}, author = {C.J. P{\'e}rez-Jim{\'e}nez and J. Campos and M. Silva} }