Eisenstadt, Shmuel Noah
The Political systems of empires
Free Press, 1967
 Buku Teks SO
Eisenstadt, Shmuel Noah
The political system of empires
Free Press, 1969
 Buku Teks
African political systems
edited by M. Fortes and E.E. Evans-Pritchard
Oxford University Press, 1950
 Buku Teks SO
Easton, David
A systems analysis of political life
John Wiley & Sons, 1965
 Buku Teks SO
Maor
Political Parties & Party Systems
 Buku Teks