Acta Mathematica Sinica, English Series
Acta Mathematica Sinica, English Series > 2004 > 20 > 5 > 943-948
Acta Mathematica Sinica, English Series > 2004 > 20 > 5 > 943-948
Acta Mathematica Sinica, English Series > 2004 > 20 > 5 > 943-948
Acta Mathematica Sinica, English Series > 2004 > 20 > 5 > 943-948