Sitepu, R., M. Nasution, and A. Halim. “The Influence of Product Innovation, Promotions, and Prices on the Decision to Purchase Oppo Brand Smartphones at the Aulia Ponsel Store Rantauprapat”. Indonesian Interdisciplinary Journal of Sharia Economics (IIJSE), Vol. 6, no. 3, Dec. 2023, pp. 3499-0, doi:10.31538/iijse.v6i3.5634.