Tong, Keith S. T., author
Routledge, 1995
Buku Teks
Vaccari, Oreste
Charles E. Tuttle, 1952
Buku Teks
Coggle, Paul, author
Teach Youeself Books, 1991
Buku Teks
Evans, Joyce J., author
John Wiley & Sons, 2003
Buku Teks
Cassar, Mario-Paul, author
Quantum Publishing, 2000
Buku Referensi