Books from the Past
Welsh Books Council

GWales.com
Welsh Books Council

Google Book Search
Search and preview millions of books from libraries and publishers worldwide

The Honourable Society of Cymmrodorian
Founded in 1751 for the encouragement of Literature, Science and the Arts as connected with Wales

Internet Archive
An internet library of historical collections - search by keyword e.g. Wales, Aberystwyth

Digitized Collections
National Library of Wales

Sources for Research in Welsh Genealogy
Library of Congress

YLolfa
Y Lolfa is one of Wales' leading printers and publishers