@article{DAN_1990_311_6_a0,
     author = {V. L. Ven and Yu. A. Krysov},
     title = {Aggregation and approximation in problems of parametric},
     journal = {Doklady Akademii Nauk},
     pages = {1289--1292},
     publisher = {mathdoc},
     volume = {311},
     number = {6},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1990_311_6_a0/}
}