Habib, Husein, and Adolf Pieter Lontoh. “Manajemen Pemanenan Kelapa Sawit (Elaeis Guineensis Jacq.) Di Kebun Gunung Pamela, Sumatera Utara”. Buletin Agrohorti, vol. 4, no. 2, May 2016, pp. 193-01, https://doi.org/10.29244/agrob.v4i2.15020.