@article{IM2_1969_3_4_a5,
     author = {M. K. Potapov},
     title = {The imbedding and equality of certain classes of functions},
     journal = {Izvestiya. Mathematics },
     pages = {795--813},
     publisher = {mathdoc},
     volume = {3},
     number = {4},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1969_3_4_a5/}
}