[1] F. M. Ragab: Expansion of an E-funktion in a series of products of E-funktions. Proc. Glasg. Math. Assoc. 3 (1958), 194-195. DOI 10.1017/S2040618500033700 | MR 0102616

[2] F. M. Ragab: Research report No BR-23 (1957). New York University, Inst, of Math. Science.

[3] F. M. Ragab: An expansion involving confluent hypergeometric funktions. Nieuw. Archief voor Wiskunde (i), VI (1958), 52-54. MR 0097548

[4] Mac-Robert T. M.: Functions of a Complex Variable. (4th edition), London 1954.

[5] F. M. Ragab: Integration of E-functions with regard to their parameters. Proc. Glasg. Math. Assoc. 3 (1956), 94-98. MR 0090670

[6] F. M. Ragab: Integration of E-functions and related functions with respect to their parameters. Proceedings, Konikl. Nederl. Ak. van Wetenschappen 61 (1958), 335 - 340. MR 0097547 | Zbl 0083.05603

[7] W. B. Bailey: Generahzed hypergeometric functions. Cambridge tracts in Math. No 32, Cambridge.