@article{MZM_2009_86_1_a5,
     author = {M. V. Ignat'ev},
     title = {Orthogonal {Subsets} of {Classical} {Root} {Systems} and {Coadjoint} {Orbits} of {Unipotent} {Groups}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {65--80},
     publisher = {mathdoc},
     volume = {86},
     number = {1},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2009_86_1_a5/}
}