Felix Klaedtke Stefan Ratschan Zhikun She Language-Based Abstraction Refinement for Hybrid System Verification. 151-166 2007 conf/vmcai/2007 VMCAI http://dx.doi.org/10.1007/978-3-540-69738-1_11 db/conf/vmcai/vmcai2007.html#KlaedtkeRS07