Wei-Jie Mao Yuan-Yuan Zhang Robust Control of Linear Continuous-Time Polytopic Systems and Application to an Electro-Hydraulic Servo System. 401-409 2008 ICIRA (1) http://dx.doi.org/10.1007/978-3-540-88513-9_43 conf/icira/2008-1 db/conf/icira/icira2008-1.html#MaoZ08