Andrea Balluchi Luca Benvenuti Maria Domenica Di Benedetto Alberto L. Sangiovanni-Vincentelli Design of Observers for Hybrid Systems. 76-89 2002 conf/hybrid/2002 HSCC http://link.springer.de/link/service/series/0558/bibs/2289/22890076.htm db/conf/hybrid/hscc2002.html#BalluchiBBS02