@article{DAN_1992_326_3_a2,
     author = {S. A. Vakhrameev},
     title = {Morse theory for a class of optimal control problems},
     journal = {Doklady Akademii Nauk},
     pages = {404--408},
     publisher = {mathdoc},
     volume = {326},
     number = {3},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_326_3_a2/}
}