400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=divina+commedia,+s'aggiungono+le+varie+lezioni+[&c.]+da+C.L.+Fernow+dante+alighieri 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.