Here are some useful links to other online resources. Please note the BTA is not responsible for any content on these websites.
Undertaking Research. Full-text guidance on philatelic research, courtesy of the Royal Philatelic Society, London. (Please note these are general guides applicable to all classes of philately).
David R Beech MBE FRPSL Philatelic Research - A Basic Guide
Charles Oppenheim FRPSL What Philatelists Need to Know About Copyright
Please note: these libraries are both closed during the coronavirus restrictions. Once reopened please check their websites for arrangements to visit.
Full Text Resources
Collecting Slogan Postmarks. 5 volumes covering 1917 - 1999. Courtesy of the Great Britain Philatelic Society
Special Event Postmarks of the United Kingdom. 5 volumes covering 1851 - 2013. Courtesy of the Great Britain Philatelic Society
Specialist Societies with themed interest
Stamps listed thematically
Colnect collectables catalog. Stamp listings by very detailed subject list..
Free Stamp Catalogue Free world catalogue with virtually every stamp/series/block from 1920 to date, plus many pre-1920.. Indexed by theme.
History of the Postcard Royal Mail
Postcard History Smithsonian Institution
Postcard Pages. Postcard Traders Association
Sites of General Interest
them@com: News of the world of thematic philately