1.

German Patent and Trade Mark Office (DPMA)

http://www.dpma.de

2.

European Patent Office (EPA)

http://www.european-patent-office.org/index.en.php

3.

US-Patent and Trademark Office (USPTO)

http://www.uspto.gov

4.

Office for Harmonization in the International Market (HABM)

http://oami.europa.eu/en/default.htm

5.

World Intellectual Property Organization (WIPO)

http://www.wipo.int.

Intellectual property databases hosted by WIPO on the Internet:

PCT database (first page data)

http://ipdl.wipo.int oder http://pctgazette.wipo.int

USPTO Patent Bibliographic and Full-Text Database

http://ipdl.wipo.int oder http://www.uspto.gov/patft/index.html