Ningrum, R. W. ., P. I. A. . Ningtyas, A. S. . Hidayati, and H. Hamamah. “Developing Syllabus for IELTS Preparation Program: Focus on Grammar for Adult Learners”. NOBEL: Journal of Literature and Language Teaching, vol. 12, no. 2, Sept. 2021, pp. 260-76, doi:10.15642/NOBEL.2021.12.2.260-276.