@article{IM2_1988_31_1_a4,
     author = {A. V. Dmitruk},
     title = {Quadratic conditions for {a~Pontryagin} minimum in an optimal control problem linear in the {control.~II.~Theorems} on weakening equality constraints},
     journal = {Izvestiya. Mathematics },
     pages = {121--141},
     publisher = {mathdoc},
     volume = {31},
     number = {1},
     year = {1988},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1988_31_1_a4/}
}