@article{VMP_2007_8_2_a0,
     author = {M. M. Potapov},
     title = {A more accurate threshold in bilateral control and observation problems for the wave equation},
     journal = {Numerical methods and programming},
     pages = {147--153},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMP_2007_8_2_a0/}
}