Mahmudah, M., E. A. Afrida, T. Koryati, and D. Wahyudi. “Impact of Sustainable Agricultural Practices: Quality Aspects of Organic and Conventional Arabica Coffee Planting Systems in Karo Regency North Sumatra Indonesia”. Contributions of Central Research Institute for Agriculture, vol. 19, no. 4, Oct. 2025, pp. 178-84, https://ejournal.cria.or.id/index.php/ccria/article/view/361.