@article{MZM_1986_39_2_a12,
     author = {A. B. Korchagin},
     title = {$M$-curves of degree~9: {New} prohibitions},
     journal = {Matemati\v{c}eskie zametki},
     pages = {277--283},
     publisher = {mathdoc},
     volume = {39},
     number = {2},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1986_39_2_a12/}
}