8Nelson C R, Plosser C R. Trends and random walks in macro econmic time series: some evidence and implications[J]. Journal of Monetary Economics, 1982, 10(2): 139-162.
9Stock J H, Watson M W. Interpreting the evidence on money-income causality[J]. Journal of Econometrics, 1989, 40(1): 161-181.
10Owoye O, Onafowora O A. The relative importance of monetary and fiscal policies in selected African countries[J]. Applied Economics, 1994, 26(11): 1083-1091.