@article{MZM_1987_42_1_a1,
     author = {M. R. Ismagulov},
     title = {Sharp estimates of approximation of periodic continuous functions by regular splines},
     journal = {Matemati\v{c}eskie zametki},
     pages = {9--20},
     publisher = {mathdoc},
     volume = {42},
     number = {1},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1987_42_1_a1/}
}