(原始内容存档于2017-08-18) Collins, Beverley; Mees, Inger M., The Phonetics of English and Dutch (PDF) 5th, Leiden: Brill Publishers, 2003 [First published 1981] [2018-02-15]
Goeman, Ton; van de Velde, Hans. Co-occurrence constraints on /r/ and /ɣ/ in Dutch dialects. van de Velde, Hans; van Hout, Roeland (编). 'r-atics. Brussels:
(原始内容存档于2017-08-18) Collins, Beverley; Mees, Inger M., The Phonetics of English and Dutch (PDF) 5th, Leiden: Brill Publishers, 2003 [First published 1981] [2018-01-17]