@article{ZNSL_2008_358_a6,
     author = {V. G. Durnev and O. V. Zetkina},
     title = {On equations in free semigroups with certain constraints on their solutions},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {120--129},
     publisher = {mathdoc},
     volume = {358},
     year = {2008},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2008_358_a6/}
}