Tong, D. H., Loc, N. P. ., Uyen, B. P. ., & Giang, L. T. . (2019). Developing the Competency of Mathematical Modelling: A Case Study of Teaching the Cosine and Sine Theorems. International Journal of Learning, Teaching and Educational Research, 18(11), 18–37. Retrieved from http://www.ijlter.net/index.php/ijlter/article/view/437