@article{DAN_1980_250_5_a21,
     author = {M. A. Grinfel'd},
     title = {On the linear theory of head wave},
     journal = {Doklady Akademii Nauk},
     pages = {1109--1111},
     publisher = {mathdoc},
     volume = {250},
     number = {5},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_250_5_a21/}
}