中国科学院数学与系统科学研究院期刊网
AMS
Global Existence of Small Solutions for Cubic Quasi-linear Klein-Gordon Systems in One Space Dimension
Dao Yuan FANG, Ru Ying XUE
Acta Mathematica Sinica . 2006, (4): 1085 -1102 .  DOI: 10.1007/s10114-005-0668-4