%0 Journal Article %T Total Cross Sections for Heavy Flavour Production at HERA %A S. Frixione %A M. L. Mangano %A P. Nason %A G. Ridolfi %J Physics %D 1994 %I arXiv %R 10.1016/0370-2693(95)00163-F %X We compute total cross sections for charm and bottom photoproduction at HERA energies, and discuss the relevant theoretical uncertainties. In particular we discuss the problems arising from the small-$x$ region, the uncertainties in the gluon parton density, and the uncertainties in the hadronic component of the cross section. Total electroproduction cross sections, calculated in the Weizs\"acker-Williams approximation, are also given. %U http://arxiv.org/abs/hep-ph/9412348v1