Massie, Joseph L., author
Prentice-Hall, 1985
Buku Teks
Peterson, Robin
New York, N.Y., Wiley / Hamilton
Buku Teks
Barraclough, Geoffrey, 1908-1984
Penguin Books, 1967
Buku Teks
Audi, Robert, author
Routledge, 2011
Buku Teks
Diamond, Jay, author
Prentice-Hall, 1975
Buku Teks