Cooper, Phillip J., author
Thomson Wadsworth, 2005
Buku Teks
Le Sueur, A.P. (Andrew P.), author
Oxford University Press, 2013
Buku Teks
Raymond W. Cox III
Routledge, 2009
Buku Teks
Jayakumar, S., author
Singapore University Press, 1974
Buku Teks
Simon, Herbert A., author
Alfred A. Knopf, 1973
Buku Teks