1. Anderson, B.D.O. and Kailath, T: Some integral equations with non-symmetric separable kernels, SIAM J. Appl. Math. 20 (4) (1971), 659–669.
2. Bart, Η., Gohberg, I. and Kaashoek, M.A.: Minimal Factorization of Matrix and Operator Functions. Operator Theory: Advances and Applications, Vol. 1, Birkhäuser Verlag, Basel etc., 1979.
3. Bart, H., Gohberg, I., Kaashoek, M.A. and Van Dooren, P.: Factorizations of transfer functions, SIAM J. Control Opt. 18 (6) (1980), 675–696.
4. Daleckii, Ju. L. and Krein, M.G.: Stability of solutions of differential equations in Banach space, Transl. Math. Monographs, Vol. 43, Amer. Math. Soc., Providence R.I., 1974.
5. Gohberg, I. and Kaashoek, M.A.: Time varying linear systems with boundary conditions and integral operators, I. The transfer operator and its properties, Integral Equations and Operator Theory 7 (1984), 325–391.