Me pēnei te tohu i te whārangi:
Mike Scarsbrook and Kit Rutherford, 'Ngā whakaahua, ngā rauemi katoa', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/mi/water-quality/media (accessed 30 September 2023)
He kōrero nā Mike Scarsbrook and Kit Rutherford, i tāngia i te 24 Nov 2008, updated 18 Jul 2016