@article{ZHOU Shi-Feng:6, author = {ZHOU Shi-Feng}, title = {}, publisher = {Journal of Guizhou University of Finance and Economics}, year = {2010}, journal = {Journal of Guizhou University of Finance and Economics}, volume = {28}, number = {5}, eid = {6}, numpages = {0}, pages = {6}, keywords = {}, url = {https://gcxb.gufe.edu.cn/EN/abstract/article_8374.shtml}, doi = {} }