S. A. Hujazie, Nedhal. “Investigation of the Focal and Zoom Properties for Three-Element Cylindrical Electrostatic Lens”. Rafidain Journal of Science 21, no. 6 (September 1, 2010): 40–51. Accessed October 5, 2025. https://alaw.uomosul.edu.iq/index.php/rsci/article/view/47711.