Gerald Segal
Simon and Schuster, 1996
Buku Referensi
Wright, Robin B. 1948-
Tian Xia Wen Hua, 1993
Buku Teks
Pearson-Prentice Hall, 2004
Buku Teks
Gray, Colin S., author
Simon & Schuster, 1990
Buku Teks
edited by Arthur S. Banks, Alan J. Day, Thomas C. Muller
CSA Publications, 1997
Buku Referensi