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Some methods for assessing the need for non-linear models in business cycle analysis
Engel, James, (2005)
Measuring business cycles : approximate band-pass filters for economic time series
Baxter, Marianne, (1999)
Statystyczne i ekonometryczne metody badania krótkookresowych zmian stanu gospodarki
Adamowicz, Elżbieta, (1998)
A useful tool to identify recessions in the Euro-area
Bengoechea, Pilar, (2004)
Seasonal integration and the evolving seasonals model
Hylleberg, Svend, (1995)