The encyclopedia of democracy : volume III
editor in chief, Seymour Martin Lipset
Routledge, 1995
 Buku Referensi
The encyclopedia of democracy : volume IV
editor in chief, Seymour Martin Lipset
Routledge, 1995
 Buku Referensi
The encyclopedia of democracy : volume I
editor in chief, Seymour Martin Lipset
Routledge, 1995
 Buku Referensi
Tocqueville, Alexis de
Democracy in America; Volume II
Vintage Books, 1960
 Buku Teks SO
The Columbia encyclopedia; Volume II
edited by William Bridgwater dan Seymour Kurtz
Columbia University Press, 1963
 Buku Referensi