Widyasari, Titik, and Akhmad Rouf. “PENGARUH PRODUKTIVITAS TERHADAP HARGA POKOK KEBUN KARET DI JAWA TENGAH”. Jurnal Penelitian Karet 1, no. 1 (June 13, 2017): 93–102. Accessed April 3, 2025. https://ejournal.puslitkaret.co.id/index.php/jpk/article/view/327.