@article{DAN_1971_200_6_a2,
     author = {D. A. Gudkov},
     title = {Construction of a new series of $M$-curves},
     journal = {Doklady Akademii Nauk},
     pages = {1269--1272},
     publisher = {mathdoc},
     volume = {200},
     number = {6},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_200_6_a2/}
}