Billingsley, P. (1999). Convergence of Probability Measures, 2nd Edition. Wiley, New York.
Brockwell, P.J and Davis, R.A. (2002). Introductionto Time Series and Forecasting, Second Edition, 2nd Edition, New York.
Dickey, D.A. and Fuller, W.A. (1979). Distribution of the estimators for autoregressive time series with a unit root. J. Amer. Statist. Assoc. 74, 427–431.
Donsker, M.D. (1951). An invariance principle for certain probabilitylimit theorems. Mem. Amer. Math. Soc. 6, 1–12.
Gould, J.P. and C.R. Nelson. (1974). The Stochastic Structure of the Velocity of Money, American Economic Review, 64, 405-418.
Wei, William W.S. (2006) Time series analysis: univariate and multivariate methods, 2nd Edition, Pearson, Addison Wesley.
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