Development Of Learning Media For Sunday School Children Based On Book Creator To Improve The Mastery Of Learning Materials For Sunday School Children In Pgi Member Churches In The North Tapanuli Region. JNS [Internet]. 2024 Jan. 12 [cited 2025 Jun. 24];40:197-206. Available from: https://namibian-studies.com/index.php/JNS/article/view/5899