@article{DAN_1991_318_6_a3,
     author = {V. I. Zubov},
     title = {Vortex surfaces},
     journal = {Doklady Akademii Nauk},
     pages = {1301--1304},
     year = {1991},
     volume = {318},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_318_6_a3/}
}