Alberto Casagrande Pietro Corvaja Carla Piazza Bud Mishra Decidable Compositions of O-Minimal Automata. 274-288 2008 ATVA http://dx.doi.org/10.1007/978-3-540-88387-6_25 conf/atva/2008 db/conf/atva/atva2008.html#CasagrandeCPM08