Shier, David
McGraw-Hill, 2002
Buku Teks
Jackie Ambadar, author
Yayasan Bina Karsa Mandiri, 2007
Buku Teks
Lourens, Jackie
NBLC, 1996
Buku Teks
Hill, Susan, author
Longman, [date of publication not identified]
Buku Teks
Asia-Pacific Economic Cooperation
APEC Secretariat, 1998
Buku Referensi