@article{ZNSL_1972_25_a4,
     author = {A. P. Kiselev},
     title = {High-frequency source between the branches of hyperbola},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {79--100},
     publisher = {mathdoc},
     volume = {25},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1972_25_a4/}
}