Crockatt, Richard, author
Routledge, 2003
Buku Teks
Fagen, Richard
Blackwell, 1987
Buku Teks
Liss, Sheldon B.
Westview Press, 1991
Buku Teks
Billington, Michael O., author
EIR News Service, 2000
Buku Teks
Frak, Andre Gunder, author
Monthley Review Press, 1972
Buku Teks