400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Démonstrations+évangéliques,+tr.,+reproduites+intégralement,+annotées+et+publ.+par+L.+Migne.+Intr.+[and]+18+tom.+[and]+Conclusion+démonstrations 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.