@article{INTF_1987_14_a1,
     author = {V. M. Tikhomirov},
     title = {Approximation theory},
     journal = {Itogi Nauki i Tekhniki. Seriya Sovremennye Problemy Matematiki. Fundamental'nye Napravleniya },
     pages = {103--260},
     publisher = {mathdoc},
     volume = {14},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTF_1987_14_a1/}
}