Supriadi, L.B. and Fikriah, N.L. 2023. The effectiveness analysis of direct marketing strategies at PT. Bathi Dua Putra, Balikpapan City. Jurnal Mantik. 7, 3 (Nov. 2023), 2799-2808. DOI:https://doi.org/10.35335/mantik.v7i3.4424.