@article{IM2_1990_35_1_a6,
     author = {I. G. Lysenok},
     title = {On some algorithmic properties of hyperbolic groups},
     journal = {Izvestiya. Mathematics },
     pages = {145--163},
     publisher = {mathdoc},
     volume = {35},
     number = {1},
     year = {1990},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1990_35_1_a6/}
}