The following papers contain information on the algorithms used to
compute the special functions,
Allan J. MacLeod, MISCFUN: A software package to compute uncommon
special functions. ACM Trans. Math. Soft., vol. 22, 1996, 288-301
G.N. Watson, A Treatise on the Theory of Bessel Functions,
2nd Edition (Cambridge University Press, 1944).
G. Nemeth, Mathematical Approximations of Special Functions,
Nova Science Publishers, ISBN 1-56072-052-2
B.C. Carlson, Special Functions of Applied Mathematics (1977)
N. M. Temme, Special Functions: An Introduction to the Classical
Functions of Mathematical Physics (1996), ISBN 978-0471113133.
W.J. Thompson, Atlas for Computing Mathematical Functions, John Wiley
& Sons, New York (1997).
Y.Y. Luke, Algorithms for the Computation of Mathematical Functions,
Academic Press, New York (1977).