400. That’s an error.

Google cannot redirect you to http://www.abebooks.de/servlet/SearchResults?tn=Verzeichniss+von+Gew%C3%A4chshaus-Pflanzen,+Stauden-Gew%C3%A4chsen,+B%C3%A4umen+Gestr%C3%A4uchen,+welche+im+Hamburgischen+Botanischen+Garten+abgegeben+werden+k%C3%B6nnen 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.