@article{AL_1991_30_6_a1,
     author = {Yu. L. Ershov},
     title = {Projective products of profinite groups},
     journal = {Algebra i logika},
     pages = {638--651},
     year = {1991},
     volume = {30},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1991_30_6_a1/}
}