@Article{Anninos97e,
    author = {P. Anninos and J. Mass\'o and E. Seidel and W.-M. Suen and M. Tobias},
    title = {Dynamics of Gravitational Waves in 3D: Formulations, Methods, and Tests},
    journal = {Phys. Rev. D},
    year = {1997},
    volume = {56},
    pages = {842}
}