@article{DAN_1961_139_4_a11,
     author = {A. V. Pogorelov},
     title = {On the isometric immersion of a two-dimensional {Riemannian} manifold homeomorphic to a sphere 
},
     journal = {Doklady Akademii Nauk},
     pages = {818--820},
     publisher = {mathdoc},
     volume = {139},
     number = {4},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_139_4_a11/}
}