@article{VSPUI_2013_3_a6,
     author = {Yu. K. Demjanovich and V. O. Dron and O. N. Ivantsova},
     title = {On  $B_\varphi$-spline approximation},
     journal = {Vestnik Sankt-Peterburgskogo universiteta. Prikladna\^a matematika, informatika, processy upravleni\^a},
     pages = {67--72},
     publisher = {mathdoc},
     number = {3},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VSPUI_2013_3_a6/}
}