400. That’s an error.

Google cannot redirect you to http://www.abebooks.fr/servlet/SearchResults?tn=Les+codes+expliqu%C3%A9s+par+leurs+motifs,+par+des+exemples+et+par+jurisprudence:+constitution+Belgique+expliqu%C3%A9e+par+ses+motifs+et+par+des+exemples 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.