Mishra, L. N., and Å. Fredriksen. “Measurement of Plasma Potential, Ion Saturation Current and Mach Number Using Retarding Field Energy Analyzer”. Journal of Nepal Physical Society 7, no. 2 (August 6, 2021): 76–80. Accessed January 28, 2022. https://www.nepjol.info/index.php/JNPhysSoc/article/view/38626.