Seligman, Edwin R.A., author
Columbia University Press, 1949
Buku Teks
Niebuhr, Reinhold, author
Nisbet, 1947
Buku Teks
Lloyd, Christopher
Blackwell Publishing, 1993
Buku Teks
At The Clarendon Press, 1946
Buku Teks
Stanford, Michael
Blackwell Publishers, 1998
Buku Teks