Stevanus, Charlos Togi, Jamin Saputra, and Thomas Wijaya. “PERAN UNSUR MIKRO BAGI TANAMAN KARET”. Warta Perkaretan 34, no. 1 (April 15, 2015): 11–18. Accessed July 3, 2024. https://ejournal.puslitkaret.co.id/index.php/wartaperkaretan/article/view/59.