A more general Bessel Function

Question

I am reading a paper where the author considers the more general Bessel equation $$x^2y'' + c_1xy' + (c_2x^{\alpha} + c_3)y =0.$$

The solutions are given, referencing some archaic text that my library doesn't have (1940s... and in German...) Does anyone know of a more modern reference that covers such an equation? The normal sources (Wikipedia, Bowman's book), don't seem to cover this.

Answer 1

See in : http://mathworld.wolfram.com/BesselDifferentialEquation.html

Eq.(3) and reference to Browman.