Al-Obaidi , Hassan N., و Ali A. Rashead Al-Azawy. 2020. "An Investigation Tool for Analyzing Electrostatic Lenses". مجلة المستنصرية للعلوم والتربية 17 (1):39-46. https://edumag.uomustansiriyah.edu.iq/index.php/mjse/article/view/206.