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Exact smoothing for stationary and non-stationary time series
Casals, José, (2000)
Spurious trend and cycle in the state space decomposition of a time series with a unit root
Nelson, Charles R., (1987)
Spurious Trend and Cycle in the State Space Decomposition of a Time Series with a Unit Root
Nelson, Charles R., (2021)
Autoregressive approximations of multiple frequency I(1) processes
Bauer, Dietmar, (2005)
Autoregressive approximations of multiple frequency I (1) processes