@article{SM_1974_24_3_a4,
     author = {M. M. Dzhrbashyan},
     title = {Biorthogonal systems of rational functions and best approximation of the {Cauchy} kernel on the real axis},
     journal = {Sbornik. Mathematics},
     pages = {409--433},
     publisher = {mathdoc},
     volume = {24},
     number = {3},
     year = {1974},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1974_24_3_a4/}
}