M. de Sainte-Catherine, and G. Viennot. Polynômes Orthogonaux et Applications, volume 1171 of Lecture Notes in Mathematics, Springer Berlin Heidelberg, (1985)
J. Batson, D. Spielman, and N. Srivastava. Proceedings of the 41st annual ACM symposium on Theory of computing, page 255--262. New York, NY, USA, ACM, (2009)