ROBUST PARAMETER ESTIMATION FOR RANDOM EFFECT PANEL DATA MODEL IN THE PRESENCE OF HETEROSCEDASTICITY AND INFLUENTIAL OBSERVATIONS. FJS [Internet]. 2021 Aug. 13 [cited 2025 Sep. 12];4(4):561-9. Available from: http://www.fjsadmin.fudutsinma.edu.ng/index.php/fjs/article/view/689