D. Supriadi and N. Kurniah, “THE IMPLEMENTATION OF PORTOFOLIO – BASED ON LEARNING TO INCREASE STUDENTS’ RESPONSIBILITY AND ACHIEVEMENTS (Study On Indonesia Lesson on Students of XI Grade at SMA Negeri 1 Lebong District)”, Diadik j. ilm. teknol. pendidik., vol. 9, no. 2, pp. 86–92, Aug. 2021.