@article{TIMM_2006_12_2_a11,
     author = {A. A. Melikyan},
     title = {Necessary optimality conditions for different phase portraits in a~neigh-borhood of a~singular arc},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {129--141},
     publisher = {mathdoc},
     volume = {12},
     number = {2},
     year = {2006},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2006_12_2_a11/}
}