@article{IM2_2002_66_1_a4,
     author = {A. I. Kozko},
     title = {On the order of the best approximation in spaces with asymmetric norm and sign-sensitive weight on classes of differentiable functions},
     journal = {Izvestiya. Mathematics },
     pages = {103--131},
     publisher = {mathdoc},
     volume = {66},
     number = {1},
     year = {2002},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2002_66_1_a4/}
}