STRATEGI PENGEMBANGAN EKSPOR KOPI ARABIKA (Coffea arabica) SUMATERA UTARA (Studi Kasus: Kota Medan) - Purba, Pascaria Dewi Lorent; Alumni Program Studi Agribisnis Fakultas Pertanian Universitas Sumatera Utara (JOURNAL ON SOCIAL ECONOMIC OF AGRICULTURE AND AGRIBUSINESS, 2014)