Alongkrit Chutinan Bruce H. Krogh Verification of Polyhedral-Invariant Hybrid Automata Using Polygonal Flow Pipe Approximations. 76-90 1999 conf/hybrid/1999 HSCC db/conf/hybrid/hscc99.html#ChutinanK99 http://link.springer.de/link/service/series/0558/bibs/1569/15690076.htm