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@article{AL_1970_9_4_a2, author = {Yu. M. Gorchakov and V. M. Levchuk}, title = {The approximation of free groups}, journal = {Algebra i logika}, pages = {415--421}, publisher = {mathdoc}, volume = {9}, number = {4}, year = {1970}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/AL_1970_9_4_a2/} }
Yu. M. Gorchakov; V. M. Levchuk. The approximation of free groups. Algebra i logika, Tome 9 (1970) no. 4, pp. 415-421. http://geodesic.mathdoc.fr/item/AL_1970_9_4_a2/