Sykes, W.R., West, C.J., Beever, J.E. & Fife, A.J. 2000. Kermadec Islands flora - special edition. A compilation of modern material about the flora of the Kermadec Islands. Lincoln, Canterbury, N.Z.: Manaaki Whenua Press. ISBN 0-478-09339-X
Sykes, W.R. 1969. The effect of goats on vegetation of the Kermadec Islands. Proceedings of the New Zealand Ecological Society 16: 13–16. Reference page.