@article{DAN_1972_206_5_a10,
     author = {L. V. Petukhov and V. A. Troitskii},
     title = {Variational optimization problems for hyperbolic partial differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {1065--1067},
     publisher = {mathdoc},
     volume = {206},
     number = {5},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1972_206_5_a10/}
}