Ahmad Zuhryansyah, Muhammad Nurali, Delyana Rahmawany Pulungan, Antonio Mario Sipayung and Purjianto 2022. FACTORS OF PALM OIL HARVESTERS PRODUCTIVITY. International Journal of Social Science, Educational, Economics, Agriculture Research and Technology (IJSET). 1, 9 (Aug. 2022), 559–577. DOI:https://doi.org/10.54443/ijset.v2i9.388.