@article{MZM_2006_80_2_a13,
     author = {O. D. Frolkina},
     title = {Relative {Preimage} {Problem}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {282--295},
     publisher = {mathdoc},
     volume = {80},
     number = {2},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2006_80_2_a13/}
}