1. Abramowitz, M., Stegun, I.A. (eds.): Handbook of Mathematical Functions with Formulas, Graphs and Mathematical Tables. Dover, New York (1965)
2. Alexits, Gy.: Convergence Problems of Orthogonal Series. Translated from the German by I. Földes. International Series of Monographs in Pure and Applied Mathematics, vol. 20. Pergamon, New York-Oxford-Paris (1961)
3. Andrews, G.E., Askey, R., Roy, R.: Special Functions. Encyclopedia of Mathematics and it Applications, vol. 71. Cambridge University Press, Cambridge (1999)
4. Appell, P., Kampé de Fériet, J.: Fonctions Hypergeometrique. Polynomes d’Hermite. Gautier-Villars, Paris (1926)
5. Ashbaugh, M.S., Benguria, R.D.: Universal bounds for the low eigenvalues of Neumann Laplacians in N dimensions. SIAM J. Math. Anal. 24, 557–570 (1993)