R. Hill-Rowley, L. Kirton, L. Ratnam, and S. Appanah. “THE USE OF A GRID-BASED GEOGRAPHIC INFORMATION SYSTEM TO EXAMINE ECOLOGICAL RELATIONSHIPS WITHIN THE PASOH 50-HA RESEARCH PLOT”. Journal of Tropical Forest Science (JTFS), vol. 8, no. 4, June 1996, pp. 570-2, https://jtfs.frim.gov.my/jtfs/article/view/1797.