edited by Andrew E. Hershberger
UK Wiley Blackwell,, 2014
Buku Teks
Kers, Martin, 1944-, author
Terra Zutphen, 1988
Buku Referensi
Rohen, Johannes W., author
Wolters Kluwer, 2016
Buku Referensi
Forde, Helen, author
Facet Publishing, 2007
Buku Teks
Vowels : J.P. Kelly and J.B. Heley
Majalah, Jurnal, Buletin