@article{DAN_1977_234_6_a3,
     author = {G. A. Margulis and G. A. Soifer},
     title = {A criterion for the existence of maximal subgroups of infinite index in a finitely generated linear group},
     journal = {Doklady Akademii Nauk},
     pages = {1261--1264},
     publisher = {mathdoc},
     volume = {234},
     number = {6},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1977_234_6_a3/}
}