Study of polytropes with generalized polytropic equation of state M. Azam, S. A. Mardan, I. Noureen and M. A. Rehman Eur. Phys. J. C, 76 6 (2016) 315 Published online: 08 June 2016 DOI: 10.1140/epjc/s10052-016-4154-1