Impact of certified rice seed on farmers’ income in Simalungun District, North SumatraSheila Savitri, Widyadhari F. Setyaningrum, Dorkas Parhusip, Setia S. Girsang, Fatimatuz Z.D.P. Dani, Saktyanu K. Dermoredjo, Bambang Sayaka and Alan de BrauwBIO Web Conf., 119 (2024) 02003DOI: https://doi.org/10.1051/bioconf/202411902003