Whiting, Allen S.
McGraw-Hill , 1980
Buku Teks
Mackerras, Colin, author
Longman Cheshire, 1994
Buku Teks
Yu, Yu-Lin
WLFD ROC Chapter , 1992
Buku Teks
by Franz Michael, Carl Linden, Jan Pryblyla, Jurgen Domes
Westview Press, 1990
Buku Referensi
Chang, Gordon G., author
Century, 2001
Buku Teks