1. Barnett, S., 1973, New Reductions of Hurwitz Determinants.
2. Barnett, S., 1983, Polynomials and Linear Control Systems, Chap. 3, Sect. 3.2.1.
3. Gantmacher, F.R., 1959, Applications of the Theory of Matrices, Chap. 5, Sects. 6, 13.
4. Ince, E.L., 1956, Ordinary Differential Equations, Chap. V, Sect. 5.23; Chap. VI.
5. Samuelson, P.A., 1947, Foundations of Economic Analysis, Appendix B, §36.