@article{DAN_1987_296_4_a13,
     author = {A. Yu. Belyaev},
     title = {Wave propagation in a continuous medium with periodically},
     journal = {Doklady Akademii Nauk},
     pages = {828--831},
     publisher = {mathdoc},
     volume = {296},
     number = {4},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_296_4_a13/}
}