Destler, I.M., author
Brooking Institution, 1990
Buku Teks
Snyder, Richard C., author
Free Press, 1962
Buku Teks
edited by Maurice Mullard
Routledge, 1995
Buku Teks
McNichols, Thomas J., author
McGraw-Hill, 1967
Buku Teks
McNichols, Thomas J., author
McGraw-Hill, 1972
Buku Teks