Nasra, Edi, Sri Etika, Desy Kurniawaty, Bahrizal Bahrizal, and Eka Yusmaita. 2019. “Improvement of MGMP Chemistry Teacher Competency in 50-Kota Districts on OSN Preparing Students”. Pelita Eksakta 2 (2), 134-39. https://doi.org/10.24036/pelitaeksakta/vol2-iss2/46.