@article{DAN_1980_250_4_a9,
     author = {N. A. Lar'kin},
     title = {On global solutions of nonlinear hyperbolic inequalities},
     journal = {Doklady Akademii Nauk},
     pages = {806--809},
     publisher = {mathdoc},
     volume = {250},
     number = {4},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_250_4_a9/}
}