Jordan, Peter, author
Ashgate, 2002
Buku Teks
Crawford, John, author
Aslib, 2000
Buku Teks
Edited by Ray Prytherch
Gower, 1998
Buku Teks
Crawford, John, author
Chandos Publishing, 2006
Buku Teks
edited by Maxine Melling
Facet Publishing, 2005
Buku Teks