Laqueur, Walter
The Free Press, 1973
Buku Teks
Elliot, Florence, author
Penguin Books, 1957
Buku Referensi
Huntington, Samuel P., author
The Belknap Press, 1981
Buku Teks
Makkai, Adam
Barrons, 1995
Buku Teks
Cummings, Paul, author
St. Martin's Press, 1966
Buku Referensi