L. S. L. Chua. 2000. “THE POLLINATION BIOLOGY AND BREEDING SYSTEM OF <em>NEPENTHES</em> <em>MACFARLANEI</Em> (NEPENTHACEAE)”. Journal of Tropical Forest Science (JTFS) 12 (4):635-42. https://jtfs.frim.gov.my/jtfs/article/view/1457.