Phase properties of a Jaynes-Cummings model with Stark shift and Kerr medium A.-S.F. Obada, A. M. Abdel-Hafez and M. Abdelaty Eur. Phys. J. D, 3 3 (1998) 289-294 Published online: 15 September 1998 DOI: 10.1007/s100530050176