@Article{KBL01,
  author = 	 {J.-P. Katoen and C. Baier and D. Latella},
  title = 	 {Metric Semantics for
	True Concurrent Real-Time},
  journal = 	 {Theoretical Computer Science},
  year = 	 2001,
  volume =	 254,
  number =	 {1-2},
  pages =	 {501-542}
}