@article{ND_2005_1_2_a4,
     author = {G. A. Galperin},
     title = {Two-dimensional configuration in the three-dimensional problem of four gravitating bodies},
     journal = {Russian journal of nonlinear dynamics},
     pages = {215--232},
     publisher = {mathdoc},
     volume = {1},
     number = {2},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ND_2005_1_2_a4/}
}