Voir la notice de l'article provenant de la source Math-Net.Ru
@article{DAN_1986_287_3_a0, author = {A. A. Agrachev and R. V. Gamkrelidze}, title = {Morse and {Maslov} indices for the extremals of controllable}, journal = {Doklady Akademii Nauk}, pages = {521--524}, publisher = {mathdoc}, volume = {287}, number = {3}, year = {1986}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DAN_1986_287_3_a0/} }
A. A. Agrachev; R. V. Gamkrelidze. Morse and Maslov indices for the extremals of controllable. Doklady Akademii Nauk, Tome 287 (1986) no. 3, pp. 521-524. http://geodesic.mathdoc.fr/item/DAN_1986_287_3_a0/