Jayarathne, A. and Chandrasena, W.D. 2020. INVESTIGATION OF THE EFFECTIVENESS OF USING SELF-DETERMINATION THEORY IN TEACHING SCIENCE FOR GRADE EIGHT STUDENTS: A CASE STUDY IN SRI LANKA. International Journal of Research -GRANTHAALAYAH. 7, 4 (Aug. 2020), 126–131. DOI:https://doi.org/10.29121/granthaalayah.v7.i4.2019.881.