Greenbaum, Sidney
Longman , 1990
Buku Teks
Parrot, Martin, author
Cambridge University Press, 2003
Buku Teks
Makkink, H.J., author
Nijgh and Van Ditmar, 1951
Buku Teks
Murphy, Raymond, author
Cambridge University Press, 1998
Buku Teks
Kaplan, Jeffrey P., author
Prentice Hall International, 1995
Buku Teks