@article{DE_1990_26_1_a18,
     author = {V. M. Govorov and \`E. K. Safiev},
     title = {Uniqueness of the classical solution of a mixed problem for a hyperbolic equation with unbounded lower coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {154--157},
     publisher = {mathdoc},
     volume = {26},
     number = {1},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1990_26_1_a18/}
}