Sarlin (2014),第18頁. Sarlin, Mika, Sounds of Romanian and their spelling, Romanian Grammar 2nd, Helsinki: Books on Demand GmbH: 16–37, 2014 [First published 2013] [2018-02-15], ISBN 978-952-286-898-5, (原始内容存档于2019-07-17)
Sarlin (2014),第18頁. Sarlin, Mika, Sounds of Romanian and their spelling, Romanian Grammar 2nd, Helsinki: Books on Demand GmbH: 16–37, 2014 [First published 2013] [2018-02-15], ISBN 978-952-286-898-5, (原始内容存档于2019-07-17)
Thomas (2001),第27–28頁. Thomas, Erik R., An acoustic analysis of vowel variation in New World English, Publication of the American Dialect Society 85, Duke University Press for the American Dialect Society, 2001, ISSN 0002-8207