Ekasari, Dana, and Siti Wulandari. “Pengembangan Modul Elektronik Berbasis Kurikulum 2013 Pada Mata Pelajaran Korespiondensi Kelas X OTKP 1 Di SMK PGRI 13 Surabaya”. Journal of Office Administration : Education and Practice 1, no. 3 (December 1, 2021): 351-363. Accessed May 4, 2024. https://ejournal.unesa.ac.id/index.php/joa/article/view/43407.