1. A. Erdelyi, W. Magnus, F. Oberhettinger andF. Tricomi:Tables of Integral Transforms, vol.2 (New York, 1954), ch. XII.
2. A. Bottino, A. M. Longoni andT. Regge:Nuovo Cimento,23, 954 (1962), eqs. (1.4) and (1.6).
3. A. Erdelyi, W. Magnus, F. Oberhettinger andF. Tricomi:Higher Trascendental Functions, vol.2 (New York, 1954), p. 88, (referred as to H.T.F.).
4. W. Kohn:Phys. Rev.,84, 495 (1951).
5. H.T.F., vol.1, p. 49.