@article{DAN_1963_149_2_a23,
     author = {I. G. Fikhtengol'ts},
     title = {Einstein's tensor of the fourth rank},
     journal = {Doklady Akademii Nauk},
     pages = {308--311},
     publisher = {mathdoc},
     volume = {149},
     number = {2},
     year = {1963},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1963_149_2_a23/}
}