中国科学院数学与系统科学研究院期刊网
Oblique Derivative Problems for Second Order Nonlinear Equations of Mixed Type with Degenerate Hyperbolic Curve
Guo Chun WEN
Acta Mathematica Sinica . 2011, (10): 2051 -2064 .  DOI: 10.1007/s10114-011-8602-4