1. Slotine, J.-J.E., Hedrick, J.K., Misawa, E.A.: On sliding observers for nonlinear systems. J. Dyn. Syst. Measur. Control 109(3), 245–252 (1987)
2. Levant, A.: Robust exact differentiation via sliding mode technique. Automatica 34(3), 379–384 (1998)
3. Levant, A.: Higher order sliding: differentiation and black-box control. In: Proceedings of the 39th IEEE Conference on Decision and Control, vol. 2, pp. 1703–1708 (2000)
4. Levant, A.: Higher-order sliding modes, differentiation and output-feedback control. Int. J. Control 76(9–10), 924–941 (2003)
5. Emaru, T., Tsuchiya, T.: Research on estimating the smoothed value and the differential value of the distance measured by an ultrasonic wave sensor. In: Proceedings. 2000 IEEE/RSJ International Conference on Intelligent Robots and Systems, vol. 2, pp. 1291–1297 (2000)