@article{TIMM_2007_13_2_a14,
     author = {Yu. N. Subbotin},
     title = {Approximations by polynomial and trigonometric splines of third order preserving some properties of approximated functions},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {156--166},
     publisher = {mathdoc},
     volume = {13},
     number = {2},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2007_13_2_a14/}
}