@article{MZM_1997_61_5_a8,
     author = {V. A. Okulov},
     title = {A~multidimensional analog of a~theorem due to {Zygmund}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {717--727},
     year = {1997},
     volume = {61},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1997_61_5_a8/}
}