Afifah, Septi Nur, and Iskandar Lubis. “Faktor Penentu Produktivitas Tenaga Kerja Panen Kelapa Sawit, Kalimantan Timur”. Buletin Agrohorti, vol. 4, no. 2, May 2016, pp. 215-23, https://doi.org/10.29244/agrob.v4i2.15024.