Lehnebach, C.A., Robertson, A.W. & Hedderley, D., 2005. Pollination studies of four New Zealand terrestrial orchids and the implication for their conservation. New Zealand Journal of Botany, 43, pp.467-477. Available at: http://www.online-keys.net/sciaroidea/2000_/Lehnebach&al2005_NZJournBot.pdf.