中国科学院数学与系统科学研究院期刊网
BOUNDARY VALUE PROBLEMS FOR QUASILINEAR POSITIVE SYMMETRIC SYSTEMS AND THEIR APPLICATIONS TO MIXED EQUATIONS
谷超豪
Acta Mathematica Sinica, Chinese Series . 1978, (2): 119 -129 .  DOI: 10.12386/A1978sxxb0013