哪位朋友能帮我下一下这几篇文章，十分感谢！
1、
篇名：Market efficiency and cointegration: an application to the sterling and deutschemark exchange markets
作者：Craig S. Hakkio;Mark Rush
链接：http://www.sciencedirect.com/science/article/pii/0261560689900156
2、
篇名：Examining the validity of a test of futures market efficiency: A comment
作者：Chung-Hua Shen;Lee-Rong Wang
链接：http://onlinelibrary.wiley.com/d ... 3990100209/abstract
3、
篇名：Estimation of Common Long-Memory Components in Cointegrated Systems
作者：Gonzalo,Jesus;Granger,Clive
链接：http://www.jstor.org/sici?sici=0735-0015(1995)13:1<27>2.0.CO;2-