@article{10_4064_am33_3_7,
     author = {Changxing Miao and Youbin Zhu},
     title = {Invariants, conservation  laws  and time decay
  for  a nonlinear system of {Klein{\textendash}Gordon
} equations  with {Hamiltonian} structure},
     journal = {Applicationes Mathematicae},
     pages = {323--344},
     publisher = {mathdoc},
     volume = {33},
     number = {3-4},
     year = {2006},
     doi = {10.4064/am33-3-7},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/am33-3-7/}
}