Design of Optimal State Controllers in the Frequency Domain (1987) Wurmthaler C, Hippe P Journal article, Original article The relation between pole-zero location and input-output behaviour of linear dynamical systems and its consequences for identification model order reduction and controller design (1987) Hippe P Journal article, Original article Measuring the frequency oscillations in power supply systems with the aid of an observer-based filter (1987) Hippe P Journal article, Original article Eine Bemerkung zur Pol-Nullstellen-Kompensation in Regelkreisen (1985) Hippe P Journal article, Original article Systematische Auslegung von Zustandsregelkreisen im Frequenzbereich Systematic design of state controllers in the frequency domain (1983) Hippe P Journal article, Original article A measure for the influence of feedback control on the dynamics of linear, timeinvariant systems (1982) Hippe P Journal article, Original article A minimal-order servo compensator includung disturbance rejection (1981) Wurmthaler C, Hippe P Journal article, Original article A simple method to design state controllers with disturbance rejection (1981) Wurmthaler C, Hippe P Journal article, Original article