@article{DAN_1987_295_1_a7,
     author = {S. V. Emel'yanov and S. K. Korovin and S. V. Nikitin},
     title = {Classification of singularities and criteria for the controllability of bilinear systems on the plane},
     journal = {Doklady Akademii Nauk},
     pages = {42--46},
     publisher = {mathdoc},
     volume = {295},
     number = {1},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_295_1_a7/}
}