United States Patent and Trademark Officehttp://www.uspto.gov/
International Trademark Associationhttp://www.inta.org/
Network Solutions WHOIS Searchhttp://www.networksolutions.com/whois/index.jsphttp://www.networksolutions.com/whois/index.jsp
Trademark Offices Worldwidehttp://www.intellectual-property.gov.uk/resources/trade_marks/offices_worldwide.htm
United States Department of Commerce http://www.commerce.gov
World Intellectual Property Organizationhttp://www.wipo.int/portal/index.html.en
United States Customs and Border Protectionhttp://iprs.cbp.gov
Madrid Express Databasehttp://www.wipo.int/ipdl
ROMARINhttp://www.wipo.int/madrid/en/romarin/index.htm