Buckley, T.R., Stringer, I., Gleeson, D., Howitt, R., Attanayake, D., Parrish, R., Sherley, G., Rohan, M. 2011 A revision of the New Zealand Placostylus land snails using mitochondrial DNA and shell morphometric analyses, with implications for conservation., New Zealand Journal of Zoology, 38(1) (p.55)
Brook, F.J. 2003 Conservation status of the giant endemic landsnail Placostylus bollonsi on Three Kings Islands, DOC Science Internal Series, 140 (p.5)
Powell, A.W.B. 1979New Zealand Mollusca: Marine, Land and Freshwater Shells, Collins, Auckland (p.349)
Climo, F.M. 1973 The Systematics, Biology and Zoogeography of the land snail fauna of Great Island, Three Kings Group, New Zealand, Journal of the Royal Society of New Zealand, 3(4) (p.583)
Powell, A.W.B. 1948 Land Mollusca of the Three Kings Islands, Records of the Auckland Institute and Museum, 3 (p.288)
Key to Geographical Ranges
The symbols K.A.C.F.M.An. are used to indicate the geographical range of the species.
They have been adopted to give an approximation of the range of each species within New Zealand.
Aupourian - Kaipara Harbour, north around North Cape, encompassing the Three Kings Islands and south to East Cape
Cookian - Lower North Island and the northern part of the South Island