@article{TRSPY_1967_89_a3,
     author = {V. I. Burenkov},
     title = {On the additivity of the classes of $W_p^{(r)}(\Omega )$},
     journal = {Informatics and Automation},
     pages = {31--55},
     publisher = {mathdoc},
     volume = {89},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_1967_89_a3/}
}