Utami IP. Praktik Jual Beli Pre Order dengan Sistem Online: Practice of Pre-Order Buying and Selling with Online System. Al-Muamalat J. Ekon. Syariah [Internet]. 2022 Aug. 4 [cited 2025 Jun. 16];9(1):20-8. Available from: http://103.55.33.27/index.php/mua/article/view/14045