400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Scriptores+Rerum+Brunsvicensium+illustrationi+inservientes,+antiqui+omnes+et+religionis+reformatione+priores:+Opus,+quo+nonnulla+Chronica+huius+vicinarumque+regionum+et+urbium+episcopatuumque+ac+monasteriorum,+praesertim.+Ostfaliae,+res+etiam+atestinorum+longobardiae,+et+guelforum+superioris+Germaniae;+vitae+item+hominum+illustrium...+Caeteris+Germanis+aliisque+populis+rebus+suis+ad+posteritatem+transmittendis+etiam+exemplo+profuturum;+Cura+Godefridi+Guilielmi+Leibnitii+gottfried+wilhelm+leibniz 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.