@article{DAN_1992_324_4_a12,
     author = {R. R. Gadyl'shin},
     title = {On merging poles of an acoustic resonator},
     journal = {Doklady Akademii Nauk},
     pages = {773--776},
     publisher = {mathdoc},
     volume = {324},
     number = {4},
     year = {1992},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1992_324_4_a12/}
}