1. D. Alpay, A. Dijksma, J. Rovnyak and H. De Snoo, Schur Functions, Operator Colligations, and Reproducing Kernel Pontryagin Spaces, Operator Theory: Adv. Appl. 96, Birkhäuser, Basel, 1997.
2. T. Andô, Linear Operators on Kreǐn Spaces, Hokkaido University, Research Institute of Applied Electricity, Division of Applied Mathematics, Sapporo, 1979.
3. R. Arocena and M. Cotlar, Continuous generalized Toeplitz kernels in R, Portugaliae Math., 39 (1980), 419–434.
4. R. Arocena and M. Cotlar, Generalized Toeplitz kernels and Adamjam-Arov- Kre.in moment problems, Operator Theory: Adv. Appl. 4, 1982, 37–55.
5. N. Aronszan, Theory of reproducing kernels, Trans. Amer. Math. Soc., 68 (1950), 337–404.