@article{CC_2009_38_4B_a16,
     author = {Tikhomirov, Vladimir},
     title = {Lagrange principle and necessary conditions},
     journal = {Control and Cybernetics},
     pages = {1589--1605},
     year = {2009},
     volume = {38},
     number = {4B},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CC_2009_38_4B_a16/}
}