@article{RM_1994_49_2_a23,
     author = {U. U. Umirbaev},
     title = {Primitive elements of free groups},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {184--185},
     publisher = {mathdoc},
     volume = {49},
     number = {2},
     year = {1994},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1994_49_2_a23/}
}