@article{SM_1995_81_1_a1,
     author = {K. Yu. Osipenko},
     title = {The {Carath\'eodory--Fej\'er} problem and optimal recovery of derivatives in {Hardy} spaces},
     journal = {Sbornik. Mathematics},
     pages = {21--33},
     publisher = {mathdoc},
     volume = {81},
     number = {1},
     year = {1995},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1995_81_1_a1/}
}