Joni, D. A. A. W., P. Nitiasih, and L. Artini. “A COMPARATIVE STUDY OF THE EFFECT OF DIFFERENT TECHNIQUES OF COOPERATIVE LEARNING AND SELF-CONFIDENCE UPON STUDENTS’ SPEAKING COMPETENCY”. International Journal of Language and Literature, vol. 1, no. 2, Nov. 2017, pp. 133-41, doi:10.23887/ijll.v1i2.12539.