Lestari, R., Sukmawardani, Y., Subarkah, C. Z., & Farida, I. (2024). Application of Problem-Based Worksheets to Develop Higher Order Thinking Skills In The Utilization of Coconut Shells As Zn Metal Adsorbent In Laboratory Waste. Hydrogen: Jurnal Kependidikan Kimia, 12(4), 879–892. https://doi.org/10.33394/hjkk.v12i4.12191