@article{SM_1977_31_3_a3,
     author = {N. Kh. Ibragimov and E. V. Mamontov},
     title = {On the {{\CYRS}auchy} problem for the equation $u_{tt}-u_{xx}-\sum_{i,j=1}^{n-1}a_{ij}(x-t)u_{y_iy_j}=0$},
     journal = {Sbornik. Mathematics},
     pages = {347--363},
     publisher = {mathdoc},
     volume = {31},
     number = {3},
     year = {1977},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1977_31_3_a3/}
}