@article{SM_1967_3_4_a3,
     author = {G. N. Yakovlev},
     title = {Traces of functions in the space $W_p^l$ on piecewise smooth surfaces},
     journal = {Sbornik. Mathematics},
     pages = {481--497},
     publisher = {mathdoc},
     volume = {3},
     number = {4},
     year = {1967},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1967_3_4_a3/}
}