@article{SM_2008_199_1_a4,
     author = {E. A. Sevast'yanov and E. Kh. Sadekova},
     title = {Snakes as an apparatus for approximating},
     journal = {Sbornik. Mathematics},
     pages = {99--130},
     year = {2008},
     volume = {199},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2008_199_1_a4/}
}