The Assay Office, Birmingham
www.theassayoffice.co.uk

The Assay Office, London
www.assayofficelondon.co.uk

The Goldsmith's Company
www.thegoldsmiths.co.uk

Hallmarking Convention
www.hallmarkingconvention.org

Hallmarks on the Internet
www.silverresearch.org

Online Encylopedia of Silver Marks, Hallmarks and Maker's Marks
www.925-1000.com (USA)

A Small Collection of Antique Silver and Objects of Vertu
www.silvercollection.it