COOK, S. Testing for Unit Roots: Threshold Autoregression and Asymmetric Trend Stationarity . Economic Issues, [S. l.], v. 6, n. 1, p. 59–65, 2001. Disponível em: https://mail.economicissues.org.uk/index.php/EI_OJS/article/view/72. Acesso em: 11 nov. 2026.