@article{AL_1977_16_1_a3,
     author = {V. S. Monakhov},
     title = {The product of two groups with nilpotent subgroups of index               not greater than ~2},
     journal = {Algebra i logika},
     pages = {46--62},
     publisher = {mathdoc},
     volume = {16},
     number = {1},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1977_16_1_a3/}
}