Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1970_192_5_a0, author = {B. M. Budak and E. M. Berkovich}, title = {The approximation of extremal problems}, journal = {Doklady Akademii Nauk}, pages = {959--962}, publisher = {mathdoc}, volume = {192}, number = {5}, year = {1970}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1970_192_5_a0/} }
B. M. Budak; E. M. Berkovich. The approximation of extremal problems. Doklady Akademii Nauk, Tome 192 (1970) no. 5, pp. 959-962. http://geodesic.mathdoc.fr/item/DAN_1970_192_5_a0/