The Royal Historical Society bibliography is an authoritative guide to what has been written about British and Irish history from the Roman period to the present day. The Bibliography is hosted by the Institute of Historical Research, which is part of the University of London.
"This is a collection of hyperlinks to digitized editions of source-documents and literature concerning early medieval Europe that can be found on the internet today. Sources listed here are all available to the public, free of charge. Currently there are 3696 entries in this collection. "