@article{EJDE_2012__2012__a52,
     author = {Wu,  Shun-Tang},
     title = {Blow-up results for systems of nonlinear {Klein-Gordon} equations with arbitrary positive initial energy},
     journal = {Electronic journal of differential equations},
     year = {2012},
     volume = {2012},
     zbl = {1254.35032},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2012__2012__a52/}
}