Andrean, Rizky, and Hendri Hermawan Adinugraha. 2021. “Competency Problems of Halal Slappers In Indonesia: A Literature Study”. Al - Muamalat: Jurnal Hukum Dan Ekonomi Syariah 6 (1), 1 - 13. https://journal.iainlangsa.ac.id/index.php/muamalat/article/view/3525.