Estimating Restricted Gamma Regression Model by Combining Gamma Ridge Regression and Restricted Maximum Likelihood with Presence of the Multicollinearity Problem with Application. Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), [S. l.], v. 56, n. 1, p. 265–273, 2025. DOI: 10.55562/jrucs.v56i1.24. Disponível em: https://jrucs.iq/index.php/JAUCS/article/view/700. Acesso em: 9 jun. 2026.