@article{ZNSL_1994_218_a3,
     author = {N. Ya. Kirpichnikova},
     title = {On computation of the second term of the ray method for the vector of longitudinal displacements in isotropic nonhomogeneous elastic media},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {25--43},
     publisher = {mathdoc},
     volume = {218},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1994_218_a3/}
}