@article{MZM_1974_16_5_a14,
     author = {E. P. Dolzhenko and E. A. Sevast'yanov},
     title = {Approximation by rational functions in integral metrics and differentiability in the mean},
     journal = {Matemati\v{c}eskie zametki},
     pages = {801--811},
     publisher = {mathdoc},
     volume = {16},
     number = {5},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1974_16_5_a14/}
}