Nellyaningsih, N, dan R Hidayat. “The Influence of Public Relations and Direct Marketing on Purchase Decisions”. Proceeding Interuniversity Forum for Strengthening Academic Competency 1, no. 1 (Mei 29, 2019): 139–146. Diakses November 13, 2026. http://proceedings.conference.unpas.ac.id/index.php/ifsac/article/view/143.