Lasher, William R.
Western College Publishing , 2000
Buku Teks
Faguet, Dmitri
John Wiley & Sons, 2003
Multimedia
by Walter J. Wadsworth
Gemini Books, 2000
Buku Referensi
Budd, Thomas A.
Alexander Hamilton Institute, 1961
Buku Teks
Allen, David
Crest Publishing House, 2002
Buku Teks