Hofstadter, Richard
Columbia University Press , 1955
Buku Teks
Universitas Bina Nusantara; Universitas Kristen Petra, 2007
Multimedia
Johnson, Edgar N.
Cornell University Press, 1950
Buku Teks
Oceana Publications, Inc., 1964
Buku Teks
Jones, Barbara M.
[American Management Association, ], 2009
eBooks