@article{VMUMM_1995_4_a0,
     author = {T. V. Dudnikova},
     title = {A connection between the scattering matrix and the scattering amplitude for symmetric hyperbolic systems},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {3--6},
     publisher = {mathdoc},
     number = {4},
     year = {1995},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1995_4_a0/}
}