1. Adamjan, V.M., D.Z. Arov and M.G. Krein: Infinite Hankelblock matrices and related extension problems, Izv. Akad. Nauk SSR. Ser. Math. 6 (1971), 87–112 [English transl.: Amer. Math. Soc. 111 (1978), 133–156
2. Ball, J.A. and N. Cohen: Sensitivity minimization in an H
∞ norm: parametriza– tion of all suboptimal solutions, Int. J. Control 46 (1987), 785–816.
3. Doyle, J.C.: Synthesis of robust controllers, Proc. IEEE Conf. Dec. Control, 1983.
4. Doyle, J.C.: Lecture Notes in Advances in Multivariable Control, ONR/Honeywell Workshop, Minneapolis, 1984.
5. Dym, H., J. Contractive Matrices, Reproducing Kernel Hilbert Spaces and Interpolation, in preparation.