Good article in the NY Sun (from a couple of years ago), about an exhibit at the Morgan Library called Apocalypse Then featuring the Morgan's famous book of Spanish illuminated manuscripts, The Morgan Beatus:
http://www.nysun.com/arts/joy-of-fire-brimstone/51903/
http://www.nysun.com/arts/joy-of-fire-brimstone/51903/
A commercial site, OMI, selling facsimiles of illuminated manuscripts and books:
http://www.omifacsimiles.com/index.html
A portal to other sites offering facsimile editions:
