Charloq. “Improving High Order Thinking Skills With Republic Polytechnics Singapore Lecturers Through Field Trip Implementation of Biochar On Soil In Pangambatan Village, Merek District, Tanah Karo Regency”. Jurnal Pengabdian Magister Pendidikan IPA 7, no. 2 (Mei 24, 2024): 330–339. Diakses November 22, 2024. https://jppipa.unram.ac.id/index.php/jpmpi/article/view/7467.