Usman, Muhlis H., Agil Al Idrus, Aris Doyan, Harry Soeprianto, and Aliefman Hakim. 2021. “Teacher Basic Skills in Learning Science in Junior High Schools Facing the 21st Century”. Jurnal Penelitian Pendidikan IPA 7 (3):331-34. https://doi.org/10.29303/jppipa.v7i3.652.