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