Google Scholar (some articles from various research repositories & websites)
Google Books (some out-of-copyright materials available in full view)
IOE E-Prints (research output of IOE staff)
OAOPEN Library (Open Access Publishing in European Networks is a collection of peer-reviewed academic books in the Humanities and Social Sciences).
OpenDOAR: allows you to browse repositories and access pre-print materials from around the world)
UCL Discovery (research output by IOE staff since 2012 and UCL staff)
UCL IOE Press (many IOE journals are now open access)
UCL Press (open access books)