Acta Mathematica Sinica, English Series
Acta Mathematica Sinica, English Series > 2008 > 24 > 6 > 997-1004
Acta Mathematica Sinica, English Series > 2008 > 24 > 6 > 1023-1030
Acta Mathematica Sinica, English Series > 2008 > 24 > 6 > 997-1004
Acta Mathematica Sinica, English Series > 2008 > 24 > 6 > 1023-1030