@article{MZM_2020_107_2_a4,
     author = {I. N. Katkovskaya and V. G. Krotov},
     title = {On the {Continuity} of {Best} {Approximations} by {Constants} on {Balls} in {Metric} {Measure} {Spaces}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {221--228},
     publisher = {mathdoc},
     volume = {107},
     number = {2},
     year = {2020},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2020_107_2_a4/}
}