Voir la notice de l'article provenant de la source Math-Net.Ru
@article{IVM_1986_12_a7, author = {V. V. Kovtunets}, title = {Differential properties of an operator of best approximation with interpolation}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {36--42}, publisher = {mathdoc}, number = {12}, year = {1986}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1986_12_a7/} }
V. V. Kovtunets. Differential properties of an operator of best approximation with interpolation. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 12 (1986), pp. 36-42. http://geodesic.mathdoc.fr/item/IVM_1986_12_a7/