1. Almost global existence to nonlinear wave equations in three space dimensions;John;Comm Pure Appl Math,1984
2. The null condition and global existence to nonlinear wave equations;Klainerman;Lect Appl Math,1986
3. Global solutions of nonlinear hyperbolic equations for small data;Christodoulou;Comm Pure Appl Math,1986
4. The null condition for quasilinear wave equations in two space dimensions I;Alinhac;Invent Math,2001
5. Almost global existence for two dimensional incompressible isotropic elastodynamics;Lei,2012