@article{DM_1992_4_2_a15,
     author = {V. G. Durnev},
     title = {Equations with endomorphisms in free semigroups},
     journal = {Diskretnaya Matematika},
     pages = {136--141},
     publisher = {mathdoc},
     volume = {4},
     number = {2},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1992_4_2_a15/}
}