Wilhelm Braumuller,
Majalah, Jurnal, Buletin
Hannah Lewi, Wally Smith, Dirk Vom Lehn and Steven Cooke
Routledge, 2020
Buku Teks
Forde, Helen
Facet Publishing, 2007
Buku Teks
Vowels : J.P. Kelly and J.B. Heley
Majalah, Jurnal, Buletin
Forde, Helen
Facet Publishing, 2007
Buku Teks