@article{DAN_1974_216_4_a8,
     author = {I. Yu. Ryzhakov},
     title = {An analog for the disk of {Zolotarev's} problem},
     journal = {Doklady Akademii Nauk},
     pages = {740--743},
     publisher = {mathdoc},
     volume = {216},
     number = {4},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1974_216_4_a8/}
}