Wade, Peter, author
Pluto Press, 2002
Buku Teks
Banton Michael, author
Tavistock Publications, 1969
Buku Teks
Mason, Philip, author
Oxford University Press, 1970
Buku Teks
Rex, John
Oxford University Press, 1979
Buku Teks
Walter, Paul A.F., author
McGraw-Hill, 1952
Buku Teks