Widiastuti, Wiwi, Ulfiyah Rajamudin, and Isrun Isrun. 2016. “Studi Kualitas Tanah Pada Toposequen Sub Das Poboya, Kota Palu”. AGROTEKBIS : JURNAL ILMU PERTANIAN (e-Journal) 4 (5), 544-52. http://jurnal.faperta.untad.ac.id/index.php/agrotekbis/article/view/57.