@article{DAN_1966_166_6_a15,
     author = {A. G. Ramm},
     title = {Regions free of resonance poles in the scattering problem for a three-dimensional potential},
     journal = {Doklady Akademii Nauk},
     pages = {1319--1322},
     publisher = {mathdoc},
     volume = {166},
     number = {6},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1966_166_6_a15/}
}