@article{SM_2006_197_8_a1,
     author = {G. A. Akishev},
     title = {Approximation of function classes in spaces with mixed
},
     journal = {Sbornik. Mathematics},
     pages = {1121--1144},
     publisher = {mathdoc},
     volume = {197},
     number = {8},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2006_197_8_a1/}
}