Wansom, Supaporn, Sirirat Janjaturaphan, and Sakprayut Sinthupinyo. 2017. “Pozzolanic Activity of Rice Husk Ash: Comparison of Various Electrical Methods”. Journal of Metals, Materials and Minerals 19 (2). Bangkok, Thailand. https://jmmm.material.chula.ac.th/index.php/jmmm/article/view/228.