1. P. Appell and J. Kampé de Fériet, Fonctions Hypergéométriques et Hypersphériques. Polynômes d'Hermite, Gauthier-Villars, Paris (1926).
2. Y. Ben Cheikh, “Decomposition of some complex functions with respect to the cyclic group of order n,” Appl. Math. Inform., 4, 30–53 (1999).
3. G. Bretti and P. E. Ricci, “Multidimensional extensions of the Bernoulli and Appell polynomials,” Taiwanese J. Math., 8, 415–428 (2004).
4. C. Cassisa, P. E. Ricci, and I. Tavkhelidze, “Operational identities for circular and hyperbolic functions and their generalizations,” Georgian Math. J., 10, 45–56 (2003).
5. C. Cassisa, P. E. Ricci, and I. Tavkhelidze, “An operatorial approach to solutions of boundary-value problems in the half-plane,” J. Concr. Appl. Math., 1, 37–62 (2003).