1. Andrews G., Askey R., Roy R., Special functions, Cambridge University Press, Cambridge, 1999
2. Callan D., A combinatorial survey of identities for the double factorial, preprint available at http://arxiv.org/abs/0906.1317
3. Cheung P., Kac V, Quantum Calculus, Springer-Verlag, Berlin, 2002
4. De Sole A., Kac V., On integral representations of q-gamma and q-beta functions, Atti. Accad. Naz. Lincei Cl. Sci. Fis. Mat. Natur. Rend. Lincei 9. Mat. Appl., 2005, 16, 11–29
5. Díaz R., Pariguan E., On hypergeometric functions and Pochhammer k-symbol, Divulg. Mat., 2007, 15, 179–192