Everett, Charles W.
Emile Durkheim, 1966
Buku Teks SO
Charles W. Eliot, edited
P. F. Collier & Son Corporation, 1959
Buku Referensi
Postema, Gerald J.
Clarendon Press, 1986
Buku Teks
Ogden, Charles Kay, 1889-1957
Littlefield, 1959
Buku Teks SO
Mill, John Stuart
David Campbell Publisher, 1992
Buku Referensi