@article{IM2_2014_78_6_a5,
     author = {G. G. Magaril-Il'yaev and K. Yu. Osipenko},
     title = {On the best methods for recovering derivatives in {Sobolev} classes},
     journal = {Izvestiya. Mathematics},
     pages = {1138--1157},
     year = {2014},
     volume = {78},
     number = {6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2014_78_6_a5/}
}