@article{FPW08, author = {W. J. Fokkink and J. Pang and A. J. Wijs}, title = {Is timed branching bisimilarity a congruence indeed?}, journal = {Fundamenta Informaticae}, year = {2008}, volume = {87}, number = {3-4}, pages = {287--311}, url = {http://satoss.uni.lu/members/jun/papers/FI08.pdf} }