@article{MZM_1969_6_1_a5,
     author = {N. P. Khoroshko},
     title = {On the best approximation in the metric of $L$ to certain classes of functions by {Haar-system} polynomials},
     journal = {Matemati\v{c}eskie zametki},
     pages = {47--54},
     publisher = {mathdoc},
     volume = {6},
     number = {1},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1969_6_1_a5/}
}