Aldi Sinai Ferdianto Simbolon, and Erna Sulistyowati. “Sistem Purchase Order Terhadap Efisiensi Dan Pengendalian Pengadaan Barang Operasional : Studi Kasus Pada DoubleTree by Hilton Surabaya”. JURNAL EKONOMI BISNIS DAN MANAJEMEN 4, no. 3 (July 14, 2026): 435–448. Accessed July 16, 2026. https://jurnal.alimspublishing.co.id/index.php/JISE/article/view/2123.