1. Askey, R.A., Olde Daalhuis, A.B.: Generalized hypergeometric functions and meijer G-function. In: NIST Handbook of Mathematical Functions, pp. 403–418. Cambridge University Press, Cambridge (2010). Chapter 16
2. Cooke, R.G.: On the sign of Lommel’s function. J. London Math. Soc. s1-7(4), 281–283 (1932)
3. Olde Daalhuis, A.B.: Hypergeometric function. In: NIST Handbook of Mathematical Functions, pp. 383–401. Cambridge University Press, Cambridge (2010). Chapter 15
4. Olver, F.W.J., Maximon, L.C.: Bessel functions. In: NIST Handbook of Mathematical Functions, pp. 215–286. Cambridge University Press, Cambridge (2010). Chapter 10
5. Paris, R.B.: Incomplete gamma and related functions. In: NIST Handbook of Mathematical Functions, pp. 173–192. Cambridge University Press, Cambridge (2010). Chapter 8