About Hallmarks Software - Acknowledgements
Assay Offices of Great Britain (for supplying booklet 4/96 in response to my request to use the hallmark images in a computer program)
Further Reading
London Goldsmiths 1697 – 1837, their marks and lives, by Arthur G Gimwade.
There is also lots of information on the internet produced by various organisations and also the Assay Office web sites.