Three-dimensional radiative flow with variable thermal conductivity and porous medium T. Hayat, S. A. Shehzad, F. E. Alsaadi and A. Alsaedi Eur. Phys. J. Plus, 128 6 (2013) 67 Published online: 25 June 2013 DOI: 10.1140/epjp/i2013-13067-3