Putri, A. ., Deliani , S. ., & Syahputra , A. . (2022). THE EFFECT OF PROBLEM BASED LEARNING MODEL ON THE ABILITY TO WRITE PROCEDURE TEXT IN STUDENTS OF CLASS XI SMA AL–MAKSUM CINTA RAKYAT STUDY YEAR 2021-2022. LUMBUNG AKSARA, 1(2), 1–10. Diambil dari http://siakad.univamedan.ac.id/ojs/index.php/lumbung_aksara/article/view/355