Yuliantini, N. N. ., Paramita, I. G. A. D., Setyono, E. Y. ., & Suciani, N. K. . (2021). The use of whatsapp cooperative learning to improve writing ability . Journal of Applied Studies in Language, 5(2), 245–251. https://doi.org/10.31940/jasl.v5i2.245-251 (Original work published December 7, 2021)