Harahap, L. J., Komala, R. . and Ristanto, . R. H. . (2020) “Studying Ecosystem in Senior High School: The Utilization of CirGi Learning Model to Enhance Mastery of Biological Concepts”, Indonesian Research Journal in Education |IRJE|, 4(2), pp. 515-529. doi: 10.22437/irje.v4i2.9608.