The profitability analysis of rubber plantation in Batang Hari Regency and Sanggau Regency (Case study: Penerokan Village and Semoncol Village)Fajri Shoutun Nida and Tri Bastuti PurwantiniE3S Web Conf., 305 (2021) 02008DOI: https://doi.org/10.1051/e3sconf/202130502008