400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Le+christianisme+Chine,+Tartarie+et+au+Thibet:+Depuis+l'apostolat+Saint+Thomas+jusqu'à+découverte+du+Cap+Bonne-Espérance+evariste+régis+huc 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.