400. That’s an error.

Google cannot redirect you to http://www.amazon.com/exec/obidos/external-search/?field-keywords=Collection+des+m%C3%A9moires+relatifs+%C3%A0+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.