@article{AL_1992_31_2_a1,
     author = {Yu. L. Ershov},
     title = {Every projective $C_2$-group is realizable},
     journal = {Algebra i logika},
     pages = {119--131},
     year = {1992},
     volume = {31},
     number = {2},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1992_31_2_a1/}
}