Boundary and Sign Problems of Parameters along with its Solutions of the Augmented Dickey-Fuller Test. Global Journal of Science Frontier Research, [S. l.], v. 14, n. F5, p. 55–59, 2014. Disponível em: https://www.journalofscience.org/index.php/GJSFR/article/view/1422. Acesso em: 13 aug. 2026.