@article{DAN_1976_231_4_a11,
     author = {K. K. Frolov},
     title = {Upper error bounds for quadrature formulas on function classes},
     journal = {Doklady Akademii Nauk},
     pages = {818--821},
     publisher = {mathdoc},
     volume = {231},
     number = {4},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1976_231_4_a11/}
}