Kristianto, Ade. “Negosiasi Harga E-Purchasing Katalog Dalam Pengadaan Barang/Jasa Pemerintah”. Jurnal Pengadaan Barang dan Jasa 1, no. 1 (April 30, 2022): 53–60. Accessed April 18, 2025. https://journal.ifpi.or.id/index.php/jpbj/article/view/14.