@article{AL_1970_9_1_a4,
     author = {V. A. Roman'kov},
     title = {Nondistributivity of the lattice of varieties of nilpotent groups},
     journal = {Algebra i logika},
     pages = {67--72},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1970_9_1_a4/}
}