Tri Martial, Ummu Harmain, Ahmad Rizki Harahap, Mitra Musika and Muhammad Arief Tirtana 2024. Enhancing Farm Household Income Through Efficient Arabica Coffee Cultivation In Simalungun, North Sumatera. Jurnal AGRISEP: Kajian Masalah Sosial Ekonomi Pertanian dan Agribisnis. 23, 02 (Sep. 2024), 425–452. DOI:https://doi.org/10.31186/jagrisep.23.02.425-452.