Fogle, Paul T., author
Delmer, 2013
Buku Teks
Gilliam, Ronald B.
Jones and Bartlett Publishers, 2011
Multimedia
Gelfer, Marylou Pausewang, author
McGraw-Hill, 1996
Buku Teks
Cummings, Louise, author
Cambridge University Press, 2016
Buku Teks
edited by Shelagh Brumfitt
Wiley - Blackwell, 2010
Buku Teks