@article{ZNSL_1991_195_a13,
     author = {N. S. Smirnova},
     title = {On finding of dynamic equivalent wave groups propagating in the layered elastic media},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {154--160},
     publisher = {mathdoc},
     volume = {195},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1991_195_a13/}
}