Salamah bt. Selamat, Habibah bt. Mohammad, and Zaitun bt. Said. “PRESERVATION OF RUBBERWOOD BY BORON-DOUBLE VACUUM PROCESS”. Journal of Tropical Forest Science (JTFS), vol. 1, no. 2, Dec. 1988, pp. 133-9, https://jtfs.frim.gov.my/jtfs/article/view/2151.