Assapari, M. M., I. N. Martha, I. M. Sutama, and L. P. Artini. “Developing EFL Learning Materials for Adult Learners: A Case in Indonesia”. International Journal of Linguistics, Literature and Culture, vol. 5, no. 3, May 2019, pp. 32-42, doi:10.21744/ijllc.v5n3.629.