400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Diatessaron,+or,+history+our+lord+Jesus+Christ,+compiled+four+Gospels+T.+Thirlwall+thomas+thirlwall because the request was invalid.

This might be because the link was created a long time ago. Try your search again on Google. That’s all we know.