Over the years ERIC (the Education Resources Information Center) has collected and indexed many education documents from government agencies, conferences, and associations. Documents from the mid-1990s and forward have been digitized; earlier documents have been available in microfiche. ERIC has completed a huge project to contact the copyright holders of documents published between 1966-1992 and obtained permission to digitize many of them.
They have digitized about half of the collection, and now 192,000 more full text documents are available in ERIC. Look for the ‘Full Text from ERIC’ link under the citation.