1. F.R. Gantmacher, The Theory of Matrices, Vol. 1 & 2, Chelsea, New York, 1960.
2. Factorization of self-adjoint matrix polynomials with constant signature;Gohberg;Linear and Multilinear Algebra,1982
3. On Siljak's absolute stability test;Karmarkar;Proc. IEEE,1970
4. Linear Multiport Synthesis;Newcomb,1966
5. Introduction to Mathematical Systems Theory: A Behavioral Approach;Polderman,1997