Igor Peterlík Ludek Matyska Haptic Interaction with Soft Tissues Based on State-Space Approximation. 886-895 2008 EuroHaptics http://dx.doi.org/10.1007/978-3-540-69057-3_111 conf/haptics/2008e db/conf/haptics/eurohaptics2008.html#PeterlikM08