@article{AL_2019_58_6_a2,
     author = {D. O. Revin},
     title = {Submaximal and epimaximal $\mathfrak{X}$-subgroups},
     journal = {Algebra i logika},
     pages = {714--719},
     publisher = {mathdoc},
     volume = {58},
     number = {6},
     year = {2019},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2019_58_6_a2/}
}