Park, Michael Alan, author
Mayfield , 2000
Buku Teks
Sommers, Christina, author
Harcourt Brace College Pub., 1997
Buku Teks
Smith, Michael, author
Cambridge University Press , 2004
Buku Teks
Wilkins, Lee, author
Lawrence Erlabum Associates, 2005
Buku Teks
Banner, Michael
Cambridge Unuversity Press , 1999
Buku Teks