@article{ND_2020_16_2_a8,
     author = {Yu. Sachkov},
     title = {Optimal {Bang-Bang} {Trajectories} in {Sub-Finsler} {Problems} on the {Engel} {Group}},
     journal = {Russian journal of nonlinear dynamics},
     pages = {355--367},
     publisher = {mathdoc},
     volume = {16},
     number = {2},
     year = {2020},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ND_2020_16_2_a8/}
}