Retnowati, May Shinta, Faridl Noor Hilal, and Devid Frastiawan Amir Sup. 2020. “Unpaid Plastic Bag Discount Analysis Based on Islamic Law Perspective (Case Study on Waralaba Retail X in Ponorogo)”. INSLA E-Proceedings 3 (1):147-54. https://insla.usim.edu.my/index.php/eproceeding/article/view/28.