1. Orthogonal matrix functions related to the multivariable Nevanlinna-Pick problem;Bultheel;Bull. Soc. Math. Belg. Sér. B,1980
2. On a special Laurent-Hermite interpolation problem;Bultheel,1981
3. Orthogonal functions related to the Nevanlinna-Pick problem;Bultheel,1979
4. A Szegő Theory for Rational Functions;Bultheel,1990
5. Orthogonal functions similar to Szegő polynomials;Bultheel,1990