Wormholes supported by polytropic phantom energy Mubasher Jamil, Peter K. F. Kuhfittig, Farook Rahaman and Sk. A. Rakib Eur. Phys. J. C, 67 3-4 (2010) 513-520 Published online: 28 April 2010 DOI: 10.1140/epjc/s10052-010-1325-3