@article{MZM_1997_62_4_a4,
     author = {V. A. Krasnov},
     title = {On orientable real algebraic $M$-surfaces},
     journal = {Matemati\v{c}eskie zametki},
     pages = {520--526},
     publisher = {mathdoc},
     volume = {62},
     number = {4},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1997_62_4_a4/}
}