Sinaga, Falencia, et al. “Pengelolaan Pemupukan Kelapa Sawit (Elaeis Guineensis Jacq.) Di Kebun Aek Nabara, Sumatera Utara”. Buletin Agrohorti, vol. 12, no. 3, Sept. 2024, pp. 366-74, https://doi.org/10.29244/agrob.v12i3.51531.