Magstadt, Thomas M., author
Thomson wadsworth, 2005
Buku Teks
Thomson Wadsworth, 2003
Multimedia
Von der Mehden, Fred R., author
Prentice-Hall, 1969
Buku Teks
Morgenthau, Hans J., author
McGraw-Hill, 1993
Buku Teks
Von der Mehden, Fred R., author
Prentice-Hall, 1964
Buku Teks