14.1 Introduction14.2 History14.3 Roots in the Left (or Right) Half-Plane; Use of Cauchy Index and Sturm Sequences14.4 Routh’s Method for the Hurwitz Problem14.5 Routh Method—the Singular Cases14.6 Other Methods for the Hurwitz Problem14.7 Robust Hurwitz Stability14.8 The Number of Zeros in the Unit Circle, and Schur Stability14.9 Robust Schur Stability14.10 Programs on StabilityReferences