Aguirre, Adalberto, author
McGraw-Hill, Higher Education, 2009
Buku Teks
Charles A Gallagher, editor
McGraw-Hill, 2012
Buku Teks
Banton Michael, author
Tavistock Publications, 1969
Buku Teks
Mason, Philip, author
Oxford University Press, 1970
Buku Teks
Wade, Peter, author
Pluto Press, 2002
Buku Teks