OzTyTs2000
From DispersiveWiki
T. Ozawa, K. Tsutaya, Y. Tsutsumi. On the coupled system of nonlinear wave equations with different propagation speeds. Banach Center Publ., 52 (2000), Evolution equations: existence, regularity and singularities (Warsaw, 1998), 181--188. MathSciNet, arXiv.
