Dictionary of Continental Celtic Place-NamesA Celtic Companion to the Barrington Atlas of the Greek and Roman World

The Arts and Humanities Research Council project in the Department of Welsh has published a dictionary of the Continental Celtic names which appear on the maps of The Barrington Atlas of the Greek and Roman World (ed. R. J. A. Talbert, Princeton, NJ, 2000): Falileyev, Alexander, in collaboration with Ashwin E. Gohil and Naomi Ward, Dictionary of Continental Celtic Place-Names: A Celtic Companion to the Barrington Atlas of the Greek and Roman World (Aberystwyth: CMCS Publications, 2010) ISBN 978-0-9557182-3-6. The dictionary itself is only available as a book, but the searchable pdf map is available here.
There are alphabetically arranged files of place-names and of place-name elements.
On Keith Briggs's map non-punctual names (rivers, tribes, etc.) are marked by '?' instead of a dot. Names can be searched for using the F(ind) command.