Permatasari, E., C. Savitri, and S. P. Faddila. “EFFECTIVENESS OF ONE DAY PROMO IN INCREASING SALES OF NPK FERTILIZER PRODUCTS 30-6-8 IN PT. XYZ”. Jurnal Mantik, vol. 6, no. 1, May 2022, pp. 771-6, https://iocscience.org/ejournal/index.php/mantik/article/view/2371.