@article{DAN_1990_310_2_a9,
     author = {I. V. Petrova},
     title = {Some aspects of the theory of $L_2$-approximations on a hyperboloid in $R^{n,1}$},
     journal = {Doklady Akademii Nauk},
     pages = {298--304},
     publisher = {mathdoc},
     volume = {310},
     number = {2},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1990_310_2_a9/}
}