@article{DE_1989_25_3_a5,
     author = {B. Mordukhovich},
     title = {Necessary conditions for optimality in nonsmooth control problems with nonfixed time},
     journal = {Differencialʹnye uravneni\^a},
     pages = {424--434},
     publisher = {mathdoc},
     volume = {25},
     number = {3},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1989_25_3_a5/}
}