Rahayu, E. (2012). ANALISIS PROFITABILITAS DAN EFISIENSI BUDIDAYA KOPI DI PTP NUSANTARA IX (PERSERO) KEBUN GETAS SALATIGA. JSEP (Journal Of Social And Agricultural Economics), 6(3), 19-25. Retrieved from https://jurnal.unej.ac.id/index.php/JSEP/article/view/807