4Engle, R F and Granger, C W J. (1987 ) ,Cointegration and error correction : representation, estimation and testing[J]. Econometrics,55 : 251 - 286.
5Geweke J , Meese,R and Dent,W. (1983),Comparing alternative tests of causality in temporal systems:analytical and experimental evidence [J]. Journal of Econometrics,21 :161- 196.
6Dichey D A and Fuller,W A. (1979) ,Distribution of.the estimators for autoregressive time series with a unit root[J] ,Journal of the American Statistical Association, 74: 47 - 431.
7Johansen,S. (1988). Statistical analysis of cointegration vectors. Journal bf Ecomomic Dynamics and Control, 12 : 231 - 254.
8Granger ,C W J. (1969). Investigating causal relations by Jeconometric model and cross-spectral methods[J]. Econometrica ,37 : 424- 438.
