Websites
stainsfile.com
chemindustry.com
dyemakers.com - Permission for photographs given by Giles Drewett of Simpson UK Ltd
http://44.1911encyclopedia.org/D/DY/DYEING.html
www.cbi.nl/downloads/leather/qualityof_leather_goods_in_the_EU.doc
Books
Methods aof Analysis and Detection, Cambridge University Press, ISBN 0-521-78724-6
Organic Chemistry, Oxford, Clayden, Greeeves, Warren and Wothers, ISBN 0-19-850346-6