Radio-Amateur-Klub der TU Wien
Radio Amateur Club of the TU Wien: https://www.qrz.com/db/OE1XTU
Radio Amateur Club of the TU Wien: https://www.qrz.com/db/OE1XTU
Austrian Patent Office: serv.ip
German Patent and Trade Mark Office: DEPATISnet
European Patent Office: Espacenet
World Intellectual Property Organization: WIPO