The first resource to check is Derwent Innovations Index, it contains over 11 million patents from over 40 worldwide patent offices, including full text for many. For more information, go to Using Derwent Innovations Index.

If you're looking for a European patent or a U.S. patent after the 1820s, useESp@ceNet. ESp@ceNet is run by the European Patent Office, containing full text of European and worldwide patents back to the 1970s.  For more information, go to Using ESp@ceNet.

If you're looking for a U.S. patent not in ESp@ceNet, use the U.S. Patent and Trademark Office. This covers all U.S. patents from 1790 onwards. Only 10 full-text downloads a day are allowed. Full text is available in HTML format and PDF format (using the Patent Fetcher). For more information, go to Using the U.S. Patent and Trademark Office.

If you want to search the full text of a patent, use OLens. OLens searches patents from the U.S., Australia, Europe, and worldwide. Full text is available in HTML format and PDF format (for selected patents). For more information, go to Using OLens.

• Search using the patent number whenever possible. Some databases rewrite the original title and abstract in their records, but the patent number stays the same. Most patent databases are searchable by patent number.

• Unless specified otherwise, include the country code letters at the beginning of the patent number. Do not include a space between the country code and the patent number.

• The letter and number appearing at the end of some patent numbers, known as the "kind code", can be omitted.

• The author of a patent is called the "Inventor."

• If an inventor submits a patent to different countries, the patent will be in a different patent family for each country.

• The patent must be tailored for each country; for example, U.S. patents cannot include nuclear weaponry, so a nuclear patent with weapon applications may include that in other countries but not the U.S.

• For scientists, different patent families are essentially identical, as the science itself will not change.

• For medical research, the differences between patent families are important. The English version is useful to decide whether it's worth it to get the versions of the patent in others language translated.

• If patent families are relevant to you, Derwent and ESp@ceNet provide the best family information.

For tutorials on each specific resource, continue to these resources:

• Using Derwent
• Using ESp@ceNet
• Using the U.S. Patent and Trademark Office
• Using Patent Lens