German Patent and Trade Mark Office:
http://www.dpma.de/english/index.html


European Patent Office
:
http://www.european-patent-office.org


Office for Harmoniz
ation in the Internal Market (for EU trade marks):
https://euipo.europa.eu/ohimportal/en


US Patent Office:
http://www.uspto.gov


Japan Patent Office:
http://www.jpo.go.jp


World Intellectual Property Organization:
http://www.wipo.org


Patent offices worldwide:

http://www.dpma.de/service/links/patentaemter/index.html