@article{SM_1991_69_2_a5,
     author = {A. A. Bondarenko},
     title = {On the problem of the maximality of arithmetic subgroups of indefinite orthogonal groups of type~$(D_l)$},
     journal = {Sbornik. Mathematics},
     pages = {417--430},
     publisher = {mathdoc},
     volume = {69},
     number = {2},
     year = {1991},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1991_69_2_a5/}
}