1. Infinite Hankel matrices and generalized problems of Carathéodody and I. Schur;Adamyan;Funktsional. Anal. i Prilozhen.,1968
2. R. Belch, Extremal Interpolation and Nonlinear Riemann-Hilbert Problems, Ph. D. thesis, Cambridge University (1998).
3. A. Böttcher, and B. Silbermann, Analysis of Toeplitz Operators (Springer, Berlin, 2006).
4. Best uniform approximation by analytic functions;Carleson;Ark. Mat.,1972
5. Nonlinear Riemann-Hilbert problem for bordered Riemann surfaces;Černe;Amer. J. Math.,2004