Dutson, Stuart, author
Global Law and Business, 2012
Buku Teks
British Council, 1991
Buku Referensi
Jasion, Jan T., author
Ashgate Publishing Limited, 1991
Buku Referensi
Wolverton, Van, author
Microsoft Press, 1989
Buku Teks
Dinerstein, Nelson T.
Dow Joues-Irwin, 1985
Buku Teks