Hughes, John P.
Random House, 1962
Buku Teks
Cambridge University Press, 2010
eBooks
Ladefoged, Peter, author
Blackwell publisher, 2001
Buku Teks
Editia Herningtias, author
Fakultas Ilmu Pengetahuan dan Budaya Universitas Indonesia, 2012
UI - Skripsi (Open)
Ladefoged, Peter, author
Blackwell Publishing, 2003
Buku Teks