Flynn, Roger R., author
M. Dekker, 1987
Buku Teks
Duff, Alistair S., author
Routledge, 2000
Buku Teks
edited by Andrew Booth and Anne Brice
Facet Publishing, 2004
Buku Referensi
Yerbury, Hilary, author
University of Technology, 1992
Buku Referensi
edited by Eric Davies
Aslib , 1991
Buku Teks