Packer, Herbert L., author
McGraw-Hill, 1973
Buku Teks
edited by Edward Rubin
Cambridge University Press, 2012
Buku Teks
Hanbury, Harold Grenville, author
Basil Blackwell, 1958
Buku Teks
Wiersma, William, author
Pearson/Allyn and Bacon, 2005
Buku Teks
SEAMEO Regional Language Centre, 1983
Buku Referensi