Adam, J.H., author
York Press, 1989
Buku Referensi
Malkoc, Anna Maria, author
Gramedia Pustaka Utama, 1995
Buku Teks
Goddard, Ken, author
The Bath Press, 1995
Buku Teks
Sweeney, Simon, author
Cambridge university press, 2010
Buku Teks
Rathbone, Robert R., author
Addison-Wesley Publishing Company, 1985
Buku Teks