Some addition to the generalized Riemann-Hilbert problem
  We give some additions to the article "On the generalized Riemann-Hilbert problem with irregular singularities" by Bolibruch, Malek, Mitschi (math/0410483). In particular, a weak GRH-problem and the GRH-problem for scalar differential equations are discussed. 
R. R. Gontsov, I. V. Vyugin