Harefa, B., E. B. Harefa, A. Telaumbanua, and A. Telaumbanua. “Development of Multimedia-Based Learning Media on Safety and Occupational Health and Environment (K3LH) Material”. Edumaspul: Jurnal Pendidikan, Vol. 8, no. 1, Mar. 2024, pp. 740-65, https://jurnal.unimen.cloud/maspuljr/article/view/7719.