@article{DAN_1974_216_6_a7,
     author = {Ho\`ang Tụy},
     title = {On an axiomatics for extremal problems and first-order necessary conditions},
     journal = {Doklady Akademii Nauk},
     pages = {1233--1236},
     publisher = {mathdoc},
     volume = {216},
     number = {6},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1974_216_6_a7/}
}