@article{SM_2018_209_3_a5,
     author = {M. I. Ganzburg},
     title = {Exact errors of best approximation for complex-valued periodic functions},
     journal = {Sbornik. Mathematics},
     pages = {421--431},
     publisher = {mathdoc},
     volume = {209},
     number = {3},
     year = {2018},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2018_209_3_a5/}
}