@article{HE Zhi-Yu:107, author = {HE Zhi-Yu}, title = {}, publisher = {Journal of Guizhou University of Finance and Economics}, year = {2011}, journal = {Journal of Guizhou University of Finance and Economics}, volume = {29}, number = {1}, eid = {107}, numpages = {0}, pages = {107}, keywords = {}, url = {https://gcxb.gufe.edu.cn/EN/abstract/article_8430.shtml}, doi = {} }