400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Ragione+di+adoprar+sicuramente+l'arme+si+da+offesa,+come+da+difesa+(etc.)+giacomo+di+grassi 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.