@article{DAN_1986_286_5_a11,
     author = {Yu. V. Trynkin},
     title = {Lagrange sets and sufficient conditions for optimality},
     journal = {Doklady Akademii Nauk},
     pages = {1071--1074},
     publisher = {mathdoc},
     volume = {286},
     number = {5},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1986_286_5_a11/}
}