@article{CMFD_2007_25_a11,
     author = {M. K. Potapov and F. M. Berisha},
     title = {On the {Connection} {Between} the {Best} {Approximation} by {Algebraic} {Polynomials} and the {Modulus} of {Smoothness} of {Order~}$r$},
     journal = {Contemporary Mathematics. Fundamental Directions},
     pages = {149--164},
     publisher = {mathdoc},
     volume = {25},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/CMFD_2007_25_a11/}
}