A phenomenological interpretation of open charm production at HERA in   terms of the semi-hard approach
  In the framework of the semi-hard (k_t-factorization) approach, we analyze the various charm production processes in the kinematic region covered by the HERA experiments. 
S.P. Baranov (Moscow), H. Jung (Lund), L. Joensson (Lund), S. Padhi   (Montreal), N.P. Zotov (Moscow)