@article{MZM_1983_34_3_a7,
     author = {A. Yu. Shadrin},
     title = {Monotone approximation of functions by trigonometric polynomials},
     journal = {Matemati\v{c}eskie zametki},
     pages = {375--386},
     year = {1983},
     volume = {34},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1983_34_3_a7/}
}