Markham May, author
McGraw-Hill, 2011
Buku Teks
Keeves, J.P.
Australian Council for Education Research, 1978
Buku Teks
Dougill, Peter
Open University Press, 1993
Buku Teks
Ellis, Sue, editor
Cambridge University Press, 2011
eBooks
edited by Joy Littell
McDougal Littell, 1985
Buku Teks