Schulz, Ernest B
[publisher not identified], 1956
Buku Teks
Arblaster, Anthony
Open University Press, 1987
Buku Teks
Eisenstadt, Shmuel Noah
The Woodrow Lilson Center Press, 1999
Buku Teks
Boix, Carles
Cambridge University Press, 2003
Buku Teks
Padover, Saul K. (Saul Kussiel)
Praeger, 1967
Buku Teks