@article{MZM_1977_22_5_a1,
     author = {N. S. Chernikov},
     title = {Groups with a~dense system of complemented nonextremal {Abelian} subgroups},
     journal = {Matemati\v{c}eskie zametki},
     pages = {611--620},
     publisher = {mathdoc},
     volume = {22},
     number = {5},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1977_22_5_a1/}
}