Mourad, Samiha
John Wiley & Sons, 2000
Buku Teks
Weyerer, Manfred
Prentice-Hall, 1992
Buku Teks
Loveday, George, author
Longman, 1995
Buku Teks
Lenk, John D., author
McGraw-Hill, 1993
Buku Referensi
Carr, Joseph J., author
Newnes, 2002
Buku Referensi