Gilbert, Martin
Avon books, 1997
Buku Teks
Mair, Christian, author
Cambridge University Press, 2006
Buku Teks
Richards, Michael D, author
John Wiley & Sons, 2014
Buku Teks
Robinson, Michael Edison, author
University Hawaii Press, 2007
Buku Teks
edited by Peter Duus
Cambridge University Press, 1995
Buku Referensi