1. Derezinski, J., Majewski, P.: From conformal group to symmetries of hypergeometric type equations. Symmetry Integrability Geometry: Methods Appl. 12, 108 (2016)
2. Dunkl, C.F., Xu, Y.: Orthogonal Polynomials of Several Variables, 2nd edn. Cambridge University Press, Cambridge (2014)
3. Erdélyi, A.: Higher Transcendental Functions, vol. 1. McGraw–Hill, New York (1953)
4. Karniadakis, G., Sherwin, S.: Spectral/hp Element Methods for Computational Fluid Dynamics. Oxford University Press, Oxford (2013)
5. Koornwinder, T.: Two-variable analogues of the classical orthogonal polynomials. In: Theory and Application of Special Functions (Proceedings of an Advanced Seminar Sponsored by the Mathematics Research Center, the University of Wisconsin, Madison, 1975), pp. 435–495