1. Graph Theory, An Introductory Course;Bollobás,1979
2. A semi-definite Lyapunov theorem and the characterization of tridiagonal D-stable matrices;Carlson;SIAM J. Algebraic Discrete Methods,1982
3. Asymptotic Behavior and Stability Problems in Ordinary Differential Equations;Cesari,1963
4. Stability of Motion;Hahn,1967
5. Differential Equations, Dynamical Systems and Linear Algebra;Hirsch,1974