Wang, Cuiping
Lin, Xinying
Guo, Dongmei
Ding, Lili
Guo, Haifeng
Xu, Guifa
Cui, Xi
Wang, Xia
Funding for this research was provided by:
National Natural Science Foundation of China (No. 39930150)
Natural Science Foundation of Shandong Province (No.Y2003C092)