@article{VMUMM_1994_1_a5,
     author = {A. A. Vdovina},
     title = {Products of squares in a free group},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {26--30},
     publisher = {mathdoc},
     number = {1},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1994_1_a5/}
}