1. Körner, T. W. Fourier Analysis. Cambridge University Press. 1988
2. Whittaker, J. M. Interpolary Function Theory, Cambridge University Press. 1935
3. Watson, G. N. Another great theoretical classic: chiefly for consultation by people who have equations they can't solve, and which seem likely to involve Bessel functions
4. Jahnke, E and Emde, F. The classic work on the functions of mathematical physics, with diagrams, charts and tables, of Bessel functions, Legendre polynomials, spherical harmonics etc
5. Abramowitz, M. and Stegun, I. A. Handbook of Mathematical Functions. Dover, New York. 1965