Herdiwijaya, Dhani, and Baju Indradjaja. “Fraktal Dan Variabilitas Dalam Siklus Bintik Matahari”. Indonesian Journal of Physics 13, no. 2 (October 31, 2016): 72-75. Accessed September 20, 2024. https://ijphysics.fi.itb.ac.id/index.php/ijp/article/view/37.