Galbraith, John Kenneth, 1908-2006, author
Houghton Mifflin, 1964
Buku Teks
World Bank Institute, 2008
Majalah, Jurnal, Buletin
Cohen, David, author
Routledge, 2006
Buku Teks
Berk, Laura E., author
Allyn and Bacon, 1997
Buku Teks
edited Charles R. Blitzer, Peter B. Clark and Lance Taylor
Oxford University Press, 1977
Buku Teks