@article{MZM_1991_49_5_a14,
     author = {S. I. Suslov},
     title = {Nonlinear bang-bang principle in $\mathbf R^n$},
     journal = {Matemati\v{c}eskie zametki},
     pages = {110--116},
     publisher = {mathdoc},
     volume = {49},
     number = {5},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_5_a14/}
}