Y. I. Izotov (1), T. X. Thuan (2, 3), N. G. Guseva (1) ((1) Bogolyubov Institute for Theoretical Physics, National Academy of Sciences of Ukraine, Kyiv, Ukraine, (2) Astronomy Department, University of Virginia, Charlottesville, USA, (3) Institut d'Astrophysique de Paris, Paris, France)
