United States Patent & Trademark Office http://www.uspto.gov
Canadian Intellectual Property Office http://cipo.gc.ca/
Japanese Patent Office http://www.jpo.go.jp/
Google Patents http://patents.google.com
This YouTube playlist,Searching Patents using Classification, was created to assist you in learning how to search patents. Most are less than 2 minutes. For further assistance contact Marian Armour-Gemmen.