Twisk, Jos W.R.
Cambridge University Press, 2006
Buku Teks
Lenk, John D.
Prentice-Hall, 1983
Buku Referensi
Bradley, Phil
Lawrence Erlbaum Associates, 1999
Buku Teks
Bradley, Phil
Library Association, 2002
Buku Teks
Bradley, Phil
Facet Publishing, 2004
Buku Teks