Solving multicollinearity problem of gross domestic product using ridge regression method. Periodicals of Engineering and Natural Sciences, [S. l.], v. 8, n. 2, p. 668–672, 2020. DOI: 10.21533/pen.v8.i2.1093. Disponível em: https://pen.ius.edu.ba/index.php/pen/article/view/1093. Acesso em: 1 may. 2026.