Simpson, David, author
Oxford University Press , 1986
Buku Teks SO
Huntington, Samuel P., author
The Belknap Press, 1981
Buku Teks
Stephen J. Wayne [et all.]
Thomson, 2005
Buku Teks
Davis, David Howard, author
Nelson-Hall Publishers, 1999
Buku Teks
edited by Edward Conrad Smith and Arnold John Zurcher
Barnes & Noble, 1966
Buku Teks