Wade, Peter, author
Pluto Press, 2002
Buku Teks
Rex, John
Oxford University Press, 1979
Buku Teks
Walter, Paul A.F., author
McGraw-Hill, 1952
Buku Teks
Taylor, Paul C., author
Polity Press, 2013
Buku Teks
Benedict, Ruth, author
The Viking Press, 1947
Buku Teks