@article{EJDE_2004__2004__a16,
     author = {Ouyang,  Tiancheng and Xie,  Zhifu and Shiqing Zhang},
     title = {Pyramidal central configurations and perverse solutions},
     journal = {Electronic journal of differential equations},
     year = {2004},
     volume = {2004},
     zbl = {1085.70013},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2004__2004__a16/}
}