中国科学院数学与系统科学研究院期刊网
The L~p Boundedness of Generalized Riesz Transform Associated with Nondivergent Elliptic Operators with Coefficients
Ming XU
Acta Mathematica Sinica, Chinese Series . 2004, (4): 657 -670 .  DOI: 10.12386/A2004sxxb0084