@article{SM_2001_192_9_a5,
     author = {A. A. Tolstonogov},
     title = {Existence of an~optimal control without convexity assumptions in a~first-order evolution system},
     journal = {Sbornik. Mathematics},
     pages = {1381--1398},
     publisher = {mathdoc},
     volume = {192},
     number = {9},
     year = {2001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2001_192_9_a5/}
}