Chinhengo, Austin M.
Cavendish Publishing, 1995
Buku Teks
Suri Ratnapala, author
Cambridge University Press, 2009
Buku Teks
Posner, Richard A., author
Harvard University Press, 2000
Buku Teks
Meyerson, Denise, author
Routledge; Cavendish, 2007
Buku Teks
Lloyd, Lord, author
Stevens & Sons, 1979
Buku Teks