@article{RM_1992_47_2_a5,
     author = {V. A. Faiziev},
     title = {Pseudocharacters of a~free subgroup invariant with respect to its endomorphisms},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {215--216},
     publisher = {mathdoc},
     volume = {47},
     number = {2},
     year = {1992},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1992_47_2_a5/}
}