@article{MZM_1998_63_2_a13,
     author = {G. G. Bilchenko and I. R. Kayumov and S. R. Nasyrov and M. F. Sadykov},
     title = {Ramified coverings of nonorientable surfaces by orientable surfaces with prescribed boundary projection},
     journal = {Matemati\v{c}eskie zametki},
     pages = {292--294},
     publisher = {mathdoc},
     volume = {63},
     number = {2},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1998_63_2_a13/}
}