Oscar H. IbarraJianwen SuZhe DangTevfik BultanRichard A. KemmererConter Machines: Decidable Properties and Applications to Verification Problems.426-435https://doi.org/10.1007/3-540-44612-5_382000conf/mfcs/2000MFCSdb/conf/mfcs/mfcs2000.html#IbarraSDBK00