1. Abramowitz, M., Stegun, I.A. (eds.): Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. Dover, New York (1992)
2. Atakishiyev, N.M., Pogosyan, G.S., Vicent, L.E., Wolf, K.B.: Separation of discrete variables in the 2-dim finite oscillator. In: Quantum Theory and Symmetries, Kraków, 2001, pp. 255–260. World Scientific, River Edge (2002)
3. Bassalygo, L.A.: Generalization of Lloyd’s theorem to arbitrary alphabet. Probl. Control Inf. Theory/Probl. Upr. Teorii Inf. 2(2), 133–137 (1973)
4. Chihara, L., Stanton, D.: Zeros of generalized Krawtchouk polynomials. J. Approx. Theory 60(1), 43–57 (1990)
5. Delsarte, P.: An algebraic approach to the association schemes of coding theory. Philips Res. Rep. Suppl. (10), vi+97 (1973)