@article{TM_1985_172_a5,
     author = {V. I. Burenkov},
     title = {Extension of functions with preservation of {Sobolev} seminorm},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {71--85},
     publisher = {mathdoc},
     volume = {172},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1985_172_a5/}
}