Niebuhr, Reinhold
Nisbet, 1947
Buku Teks SO
Lloyd, Christopher
Blackwell, 1993
Buku Teks SO
Dray, William H.
Prentice-Hall, 1993
Buku Teks SO
Collingwood, R.G.
Clarendon Press, 1946
Buku Teks SO
Hegel, George Wilhelm Friedrich
Dover, 1956
Buku Teks SO