The Free Press, 1990
Buku Teks
Kegley, Charles W. (Charles William), Jr., author
Wadsworth, 2009
Buku Teks
Rourke, John T., author
Mc Graw Hill, 2009
Buku Teks
J.A, Denny, author
LKIS Yogyakarta, 2006
Buku Teks
Barnes, James F., author
St. Martin`s Press, 1980
Buku Teks