Selvam, K. C., and S. Latha. “A Simple Square Rooting Circuit Based on Operational Amplifiers (OPAMPs)”. Engineering, Technology & Applied Science Research 3, no. 1 (February 11, 2013): 349–351. Accessed January 21, 2022. https://etasr.com/index.php/ETASR/article/view/234.