@article{DM_1997_9_2_a14,
     author = {L. P. Lisovik},
     title = {$\Sigma TC$-generated languages and relative equivalence problems},
     journal = {Diskretnaya Matematika},
     pages = {139--160},
     publisher = {mathdoc},
     volume = {9},
     number = {2},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_1997_9_2_a14/}
}