@article{DAN_1984_275_2_a6,
     author = {M. L. Gerver and N. S. Nadirashvili},
     title = {A condition for isometry of {Riemannian} metrics in the disc},
     journal = {Doklady Akademii Nauk},
     pages = {289--293},
     publisher = {mathdoc},
     volume = {275},
     number = {2},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1984_275_2_a6/}
}