Dickinson, Duo, author
McGraw-Hill, 1995
Buku Teks
Westview Press, 1997
Buku Teks
Brown, David, author
Airlife Publishing LTD, 1995
Buku Teks
Postlewaite, Philip F., author
West Publisher, 1997
Buku Teks
Altman, Edward I.
John Wiley & Sons, 1993
Buku Teks