TobingJ. C., Suwarto, and ZamanS. “Optimum Nitrogen Fertilizer Dosage for Composite and Hybrid Varieties of Maize”. Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy), Vol. 50, no. 2, Aug. 2022, pp. 139-46, doi:10.24831/jai.v50i2.40199.