Setiadji, Bambang. “Pengembangan Usaha Peternakan Sapi Perah Rakyat Kasus Cangkringan Yogyakarta”. Unisia, no. 21 (July 20, 2016): 98–104. Accessed April 4, 2025. https://journal.uii.ac.id/Unisia/article/view/5375.