Lestari, Alfiyani, and Sri Atun. “The Effectiveness of E-Module on Buffer Solutions to Improve Students’ Higher-Order Thinking Skills and Self-Regulated Learning”. JTK (Jurnal Tadris Kimiya), vol. 6, no. 2, Dec. 2021, pp. 254-66, doi:10.15575/jtk.v6i2.13772.