"RELATIVE EFFICIENCY OF RIDGE REGRESSION AND ORDINARY LEAST SQUARE ESTIMATORS ON LINEAR REGRESSION MODELS AT DIFFERENT LEVELS OF MULTICOLLINEARITY". FULafia Journal of Science and Technology , م 3, عدد 2, ديسمبر، 2017, ص 77-81, https://lafiascijournals.org.ng/index.php/fjst/article/view/83.