400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Mittheilungen+aus+Justus+Perthes'+geographischer+Anstalt+über+wichtige+neue+Erforschungen+auf+dem+Gesammtgebiete+der+Geographie+von+A.+Petermann 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.