Hanin F. ENVIRONMENTAL CONCEPT BASED PjBL (PROJECT BASED LEARNING) MODELS TO INCREASE THE OBSERVATION SKILLS OF VII GRADE STUDENTS AT SMPN 1 JENANGAN PONOROGO. smt [Internet]. 2020 Jun. 20 [cited 2024 Nov. 5];3(1):50-8. Available from: https://semesta.ppj.unp.ac.id/index.php/semesta/article/view/94