“Estimating Restricted Gamma Regression Model by Combining Gamma Ridge Regression and Restricted Maximum Likelihood with Presence of the Multicollinearity Problem with Application” (2025) Journal of Al-Rafidain University College For Sciences ( Print ISSN: 1681-6870 ,Online ISSN: 2790-2293 ), 56(1), pp. 265–273. doi:10.55562/jrucs.v56i1.24.