Ashby, Michael F.
Cambridge University Press, 2010
eBooks
Ladefoged, Peter
Blackwell publisher, 2001
Buku Teks
Hughes, John P.
Random House, 1966
Buku Teks SO
Hughes, John P.
Random House, 1966
Buku Teks SO
Ladefoged, Peter
Blackwell, 2003
Buku Teks SO