“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): 265-73. https://doi.org/10.55562/jrucs.v56i1.24.