by Joseph T. Straub
Gemini Books, 2000
Buku Referensi
Lasher, William R., author
Western College Publishing , 2000
Buku Teks
Faguet, Dmitri, author
John Wiley & Sons, 2003
Multimedia
by Walter J. Wadsworth
Gemini Books, 2000
Buku Referensi
Budd, Thomas A., author
Alexander Hamilton Institute, 1961
Buku Teks