@article{DAN_1990_313_6_a5,
     author = {I. B. Erunova and V. Ya. Rivkind},
     title = {Estimates for the rate of convergence of approximate methods for},
     journal = {Doklady Akademii Nauk},
     pages = {1306--1309},
     publisher = {mathdoc},
     volume = {313},
     number = {6},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1990_313_6_a5/}
}