@article{TM_1988_185_a15,
     author = {S. V. Plotnikova},
     title = {Investigation of time optimality properties},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {192--199},
     publisher = {mathdoc},
     volume = {185},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TM_1988_185_a15/}
}