Leicester University Press, 1997
Buku Teks
Nagle, John D.
Sage Publications, 1999
Buku Teks
Boix, Carles, author
Cambridge University Press, 2003
Buku Teks
Lodge, George C., author
Harper , [date of publication not identified]
Buku Teks
Padover, Saul K. (Saul Kussiel), author
Praeger, 1967
Buku Teks