Lippmann, Walter, author
Little, Brown, 1943.
Buku Teks
Herskovits, Melville J.
Columbia University Press, 1936
Buku Teks
Jones, Joseph Marion
Macmillan, 1944
Buku Teks
Berding, Andrew, author
Double Day, 1962
Buku Teks
Lerche, Charles O.
Prentice-Hall, 1958
Buku Teks