@article{IM2_2010_74_6_a0,
     author = {R. S. Avdeev},
     title = {Extended weight semigroups of affine spherical homogeneous spaces of non-simple semisimple algebraic groups},
     journal = {Izvestiya. Mathematics },
     pages = {1103--1126},
     publisher = {mathdoc},
     volume = {74},
     number = {6},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2010_74_6_a0/}
}