Sadjati, Ida Malati, Ernik Yuliana, and suparti suparti. “PENINGKATAN KUALITAS BUKU MATERI POKOK BERDASARKAN HASIL UJI COBA LAPANGAN”. Jurnal Pendidikan Terbuka Dan Jarak Jauh 15, no. 2 (September 14, 2014): 99–111. Accessed July 3, 2024. https://jurnal.ut.ac.id/index.php/jptjj/article/view/593.