1. F. Calogero:Lett. Nuovo Cimento 20, 254 (1977).
2. See, for instance, sect.15.51 ofG. N. Watson:A Treatise on the Theory of Bessel Functions (Cambridge U. P., 1958), p. 502.
3. P. Sabatier: private communication (to be published).
4. L. B. W. Jolley:Summation of Series (Dover, 1961), eq. (400), pp. 76–77.