Parmanoan , . H., H. Mahyuni Khairiyah, P. Sutan, and H. Fitra Syawal. “Productivity of Arenga Pinnata Merr Male Flower Stalks in South Tapanuli Regency Referring to Sustainable Agricultural Systems”. Jurnal Online PERTANIAN TROPIK, vol. 7, no. 3, Feb. 2021, pp. 303-11, doi:10.32734/jpt.v7i3.4825.