Dahrendorf, Ralf
Stanford University Press, 1975
Buku Teks SO
Hayek, Friedrich A. von [Friedrich August], 1899-1992
Routledge & Kegan Paul, 1973
Buku Teks
Mill, John Stuart
David Campbell Publisher, 1992
Buku Referensi
Walker, Patrick Gordon
Hutchinson & Company, 1951
Buku Teks SO
Handlin, Oscar
Atheneum, 1966
Buku Teks SO