This chapter is based in part on
Abramowitz and Stegun (1964, Chapter 5) by Walter Gautschi and
William F. Cahill. Walter Gautschi provided the author with a list of
references and comments collected since the original publication.
For general bibliographic reading see Andrews et al. (1999),
Jeffreys and Jeffreys (1956), Lebedev (1965), Olver (1997b),
and Temme (1996b).