Safuan, La Ode, Roedhy Poerwanto, Anas Dinurrohman Susila, and , Sobir. “Rekomendasi Pemupukan Kalium Untuk Tanaman Nenas Berdasarkan Status Hara Tanah”. Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) 39, no. 1 (September 7, 2016). Accessed October 1, 2020. http://journal.ipb.ac.id/index.php/jurnalagronomi/article/view/13194.