Zurn, Christopher F.
Cambrigde University Press , 2009
Buku Teks
Omar, Imtiaz
Kluwer Law International, 1996
Buku Teks
Carr, Robert K.
Rinehart, 1942
Buku Teks
Downs, Anthony
Harper and Row, 1975
Buku Teks
Gabin, Sanford Byron
National University Publications, 1980
Buku Teks