6Li Curt-bin,Wang Ke-cheng. A New Grey Gorecasting Model on BP Neural Network and Markov Chain [J]. J, Cent. South Univ. Technology, 2007, (5).
7WANG Qi-jie,LIAO Xin-hao,ZHOU Yong-hong etc. Hybrid grey model to forecast monitoring series with seasonality[J]. J. Cent. South Univ. Technology, 2005,(5).,.