Hanin, Fauziah. 2020. “ENVIRONMENTAL CONCEPT BASED PjBL (PROJECT BASED LEARNING) MODELS TO INCREASE THE OBSERVATION SKILLS OF VII GRADE STUDENTS AT SMPN 1 JENANGAN PONOROGO”. SEMESTA: Journal of Science Education and Teaching 3 (1):50-58. https://doi.org/10.24036/semesta/vol3-iss1/94.