@article{IM2_2011_75_4_a1,
     author = {M. V. Dolgopolov and I. N. Rodionova},
     title = {Problems involving equations of hyperbolic type in the plane or three-dimensional space with conjugation conditions on a~characteristic},
     journal = {Izvestiya. Mathematics },
     pages = {681--689},
     publisher = {mathdoc},
     volume = {75},
     number = {4},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_2011_75_4_a1/}
}