400. That’s an error.

Google cannot redirect you to http://worldcat.org/search?q=Annus positionum mathematicarum, quas defendit ac demonstravit Perill : Dom D. Wolffgangus, Philippus, Iacobus Unverzagt, baro Ebenfurt, praeside ... I. Ciermans ... jan ciermans 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.