Hewings, Martin
Cambridge University Press, 2005
Buku Teks
Greenbaum, Sidney
Longman , 1990
Buku Teks
Kaplan, Jeffrey P.
Prentice Hall International, 1995
Buku Teks
Shurter, Robert L.
McGraw-Hill, 1959
Buku Teks
Makkink, H.J.
Nijgh and Van Ditmar, 1951
Buku Teks