Bailey, Stephen K., author
Henry Holt, 1957
Buku Teks
Slocum, Stephanie A., author
Syracuse University Press, 2003
Buku Teks
ECAM Publications, 1989
Buku Teks
Schlesinger, Arthur Meier, author
W.W. Norton, 1992
Buku Teks
Tocqueville, Alexis De, author
Oxford University Press, 1961
Buku Teks