Heavy quark production at the TESLA collider and its sensitivity to the gluon content in the photon P. Jankowski, M. Krawczyk and A. De Roeck Eur. Phys. J. C, 24 4 (2002) 547-553 Published online: 21 June 2002 DOI: 10.1007/s10052-002-0937-7