Sri Ulina, Hendra Utama. The Effect of Product Quality and Promotion on Purchase Decisions on Umkm Products UD. Kunyahan Medan. IJIS [Internet]. 2025 Jul. 1 [cited 2026 May 20];4(6):1389-400. Available from: https://mryformosapublisher.org/index.php/ijis/article/view/387