1997 IUCN red list of threatened plants (1997)

Flora Malesiana Series II Pteridophyta - Rijksherbarium (Netherlands) (M. Nijhoff/W. Junk, 1978)

Flora Malesiana Series II Pteridophyta - Rijksherbarium (Netherlands) (M. Nijhoff/W. Junk, 1978)

The Gardens' bulletin, Singapore (Govt. Print. Off. [etc.], 1977)