1. MPOC. The Oil Palm Tree. https://www.palmoilhealth.org/what-is-palm-oil/the-oil-palm-tree/ (2018).
2. Ng, Y. G. et al. Risk factors of musculoskeletal disorders among oil palm fruit harvesters during early harvesting stage. Ann. Agric. Environ. Med. 22(2), 286–292 (2015).
3. Zulkifli, H., Chan K. W., Choo Y. M., & Basri, W. M. Life cycle assessment for oil palm fresh fruit bunch production from continued land use for oil palm planted on mineral soil (Part 2). J. Oil Palm Res. 22, 887–894 (2010).
4. Agri-Resources, G. How Oil Palm is Grown. https://goldenagri.com.sg/oil-palm-grown/ (2017).
5. Ng, Y. G., Bahri, M. T. S., Syah, M. Y. I., Mori, I., & Hashim, Z., Ergonomics observation: Harvesting tasks at oil palm plantation, J. Occup. Health, pp. 13-0017-FS (2013).