@article{SM_1978_34_3_a2,
     author = {Yu. I. Brodskii},
     title = {Necessary conditions for a~weak extremum in optimal control problems on an infinite time interval},
     journal = {Sbornik. Mathematics},
     pages = {327--343},
     publisher = {mathdoc},
     volume = {34},
     number = {3},
     year = {1978},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1978_34_3_a2/}
}