Simatupang L, Devi D. The preparation and characterization of Sinabung volcanic ash as silica based adsorbent. J.Pendidik.Kim [Internet]. 2016 Dec. 15 [cited 2025 Jul. 3];8(3):159-63. Available from: https://jurnal.unimed.ac.id/2012/index.php/jpk/article/view/4478