Useful Links

The following links may be useful:

https://collectingancientcoins.co.uk
An informative website with much helpful information for newcomers to collecting ancient coins.

www.bnta.net
The British Numismatic Trade Association

www.wildwinds.com
Research website for ancient coins

http://www.finds.org.uk/CCI/
The Oxford Celtic Coin Index

www.r8sceattatypes.website 
A Study on the Series R sceat