edited by Bert N. Adams, Jan Trost
Sage Publications, 2005
Buku Referensi
Mott, Sandra R., author
Addison-Wesley, 1990
Buku Teks
Routledge, 2005
Buku Teks
O`Loughlin, Maureen, author
Learning Matters, 2008
Buku Teks
Mott, Sandra R.
Addison-Wesley, 1990
Buku Teks