Jaikla, W., and M. Siripruchyanun. “A Novel Precision Current-mode Fullwave Rectifier Using Current-controlled Current Conveyors and OTAs”. Engineering and Applied Science Research, vol. 33, no. 3, Feb. 2013, pp. 287-98, https://ph01.tci-thaijo.org/index.php/easr/article/view/5997.