Reaheam, Al-Saphory. “REGIONAL BOUNDARY ASYMPTOTIC GRADIENT FULL ORDER OBSERVER VIA INTERNAL REGION”. Al-Qadisiyah Journal of Pure Science 25, no. 1 (March 3, 2020): math 40- 45. Accessed January 23, 2026. https://journalsc.qu.edu.iq/index.php/JOPS/article/view/1061.