Rosen, George
University California Press, 1966
Buku Teks
edited by John A. Wiseman
Routledge, 1995
Buku Teks
Saikal, Amin
Westview Press, 1991
Buku Teks
Arblaster, Anthony
Open University Press, 1987
Buku Teks
Oxford University Press, 1995
Buku Teks