Virginia Papailiopoulou Laya Madani Lydie du Bousquet Ioannis Parissis Extending Structural Test Coverage Criteria for Lustre Programs with Multi-clock Operators. 23-36 2008 FMICS http://dx.doi.org/10.1007/978-3-642-03240-0_6 conf/fmics/2008 db/conf/fmics/fmics2008.html#PapailiopoulouMBP08