Me pēnei te tohu i te whārangi:
Ian Popay, 'Ngā whakaahua, ngā rauemi katoa', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/mi/weeds-of-agriculture/media (accessed 12 December 2023)
He kōrero nā Ian Popay, i tāngia i te 24 Nov 2008