400. That’s an error.

Google cannot redirect you to http://www.abebooks.fr/servlet/SearchResults?tn=Du+dialecte+blaisois+et+sa+conformit%C3%A9+avec+l%27ancienne+langue+et+l%27ancienne+prononciation+fran%C3%A7aise+... 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.