中国科学院数学与系统科学研究院期刊网
AMS
The method of A -harmonic approximation and boundary regularity for nonlinear elliptic systems under the natural growth condition
Shu Hong Chen, Zhong Tan,
Acta Mathematica Sinica . 2009, (1): 133 -156 .  DOI: 10.1007/s10114-008-6005-y