@article{EJDE_2008__2008__a95,
     author = {Yang,  Jianfu and Ye,  Ying and Yu,  Xiaohui},
     title = {Existence results for strongly indefinite elliptic systems},
     journal = {Electronic journal of differential equations},
     year = {2008},
     volume = {2008},
     zbl = {1173.35454},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2008__2008__a95/}
}