Spiro, Melford E.
Harvard University Press , 1956
Buku Teks
More, Thomas, author
David Campbell Publishers, 1992
Buku Referensi
Krishna, Daya, 1924-2007, author
Sage, 2012
Buku Teks
Hamilton, R.A., author
Pinguin Books, 1958
Buku Teks
Spiro, Herbert J
Van Nostrand Reinhold, 1969
Buku Teks