@article{DAN_1995_344_6_a7,
     author = {I. G. Fikhtengol'ts},
     title = {Characteristic vectors and characteristic tensors for spherically},
     journal = {Doklady Akademii Nauk},
     pages = {756--759},
     publisher = {mathdoc},
     volume = {344},
     number = {6},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1995_344_6_a7/}
}