Bahri, S. “Studi Evaluasi Kinerja Petani Karet”. IQTISHADUNA: Jurnal Ilmiah Ekonomi Kita, Vol. 5, no. 2, Dec. 2016, pp. 107-13, https://ejournal.isnjbengkalis.ac.id/index.php/iqtishaduna/article/view/82.