LubisR. E., and LontohA. P. “Manajemen Panen Kelapa Sawit (Elaeis Guineensis Jacq.) Di Kebun Adolina, Serdang Bedagai, Sumatera Utara”. Buletin Agrohorti, Vol. 4, no. 2, May 2016, pp. 144-5, doi:10.29244/agrob.v4i2.15013.