Utari, Ratna Sari Dewi, and Maclaurin Hutagalung. “Developing an Effective Marketing Strategy for Pop Up Class Business Products for Early Childhood”. Amkop Management Accounting Review (AMAR) 6, no. 1 (June 30, 2026): 1138–1149. Accessed August 1, 2026. https://ojs.stieamkop.ac.id/index.php/amar/article/view/3403.