次閉後不圓唇元音Gruyter: 580–602, 2004, ISBN 3-11-017532-0 Bowerman, Sean, White South African English: phonology, Schneider, Edgar W.; Burridge, Kate; Kortmann, Bernd; Mesthrie
開前不圓唇元音Vicente (1967:?頁) Merrill (2008:109頁) Bekker, Ian, The vowels of South African English (PDF), 2008 [2014-04-06], (原始内容存档 (PDF)于2021-02-07) Boberg, C., The