@article{DAN_1990_312_2_a3,
     author = {F. I. Fedorov},
     title = {The metric tensor and tetrads},
     journal = {Doklady Akademii Nauk},
     pages = {277--279},
     publisher = {mathdoc},
     volume = {312},
     number = {2},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1990_312_2_a3/}
}