Ristania, Novia, and Jerry S. Justianto. “ANALISA PENGARUH HARGA, PROMOSI DAN VIRAL MARKETING TERHADAP KEPUTUSAN PEMBELIAN PADA ‘ONLINE SHOP’ S-NEXIAN MELALUI FACEBOOK”. Journal of Business Strategy and Execution, vol. 5, no. 2, June 2013, pp. 131-6, https://journal.binus.ac.id/index.php/JBSE/article/view/772.