@article{ZNSL_1994_210_a7,
     author = {N. Ya. Kirpichnikova and M. M. Popov and I. P\v{s}en\v{c}ik},
     title = {An algorithm for computation of the second term of the ray method series in an inhomogeneous isotropic medium},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {73--93},
     year = {1994},
     volume = {210},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1994_210_a7/}
}