@article{AL_1970_9_6_a1,
     author = {L. N. Vaserstein and A. V. Mikhalev},
     title = {The normal subgroups of the orthogonal group over a ring with},
     journal = {Algebra i logika},
     pages = {629--632},
     publisher = {mathdoc},
     volume = {9},
     number = {6},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1970_9_6_a1/}
}