Stichting Mathematisch Centrum
Stichting Mathematisch Centrum. Toegepaste Wiskunde

Koornwinder, T. H. (1973). Orthogonal polynomials in two variables which are eigenfunctions of two independent partial differential operators, 2 : Prepublication. In Stichting Mathematisch Centrum. Toegepaste Wiskunde (TW 137/73). Stichting Mathematisch Centrum.