@article{IM2_1994_43_2_a2,
     author = {R. R. Gadyl'shin},
     title = {Splitting of the poles of a {Helmholtz} resonator},
     journal = {Izvestiya. Mathematics},
     pages = {233--260},
     year = {1994},
     volume = {43},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1994_43_2_a2/}
}