Schepard, Andrew I., 1948-, author
Cambridge University Press, 2004
Buku Teks
University Press, 1949
Buku Teks
Mott, Sandra R., author
Addison-Wesley, 1990
Buku Teks
Routledge, 2005
Buku Teks
O`Loughlin, Maureen, author
Learning Matters, 2008
Buku Teks