@article{SM_2002_193_8_a0,
     author = {T. G. Vozmischeva and A. A. Oshemkov},
     title = {Topological analysis of the~two-centre problem on the~two-dimensional},
     journal = {Sbornik. Mathematics},
     pages = {1103--1138},
     year = {2002},
     volume = {193},
     number = {8},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2002_193_8_a0/}
}