@article{AL_1983_22_3_a1,
     author = {Yu. L. Ershov},
     title = {Involutory groups},
     journal = {Algebra i logika},
     pages = {260--275},
     publisher = {mathdoc},
     volume = {22},
     number = {3},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1983_22_3_a1/}
}