400. That’s an error.

Google cannot redirect you to http://www.amazon.com/exec/obidos/external-search/?field-keywords=Histoire+g%C3%A9n%C3%A9rale+et+impartiale+des+erreurs,+des+fautes+et+des+crimes+commis+pendant+r%C3%A9volution+fran%C3%A7aise&index=books 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.