Dark energy fluid with time-dependent, inhomogeneous equation of state I. Brevik, O.G. Gorbunova and A.V. Timoshkin Eur. Phys. J. C, 51 1 (2007) 179-183 Published online: 01 June 2007 DOI: 10.1140/epjc/s10052-007-0278-7