@inproceedings{LPT07:ICTAC,
author = {A.~Lapadula and R.~Pugliese and F.~Tiezzi},
title = {C$\clock$WS: A timed service-oriented calculus},
booktitle = {Proc. of 4th International Colloquium on Theoretical Aspects of Computing (ICTAC'07)},
publisher = {Springer},
series = {Lecture Notes in Computer Science},
volume = {4711},
pages = {275-290},
year = {2007}
}



Please, notice that the latex symbol \clock requires the package "wasysym".