3Spirtes, P. , Glymour, C. , and Scheines, R. (1993) . Causation, Prediction and Search. New York: Springer-Verlag.
4Swanson N.R. and C. W.J. Granger ( 1997 ) . Impulse Response Functions Based on a Causal Approach to Residual Orthogonalization in Vector Autoregressions. Journal of the American Statistical Association (92) : 357 -367.