Best Bet: Google Patents - Search patents from the US and many other countries
SciFinder includes patents in results and allows you to limit your search to look in patents only. You can use one of the databases above to find the full patents.
Dissertations and theses written by other people can be very useful to you in your research. They have not been peer reviewed, and you do not want to cite them as references directly. But they are a good place to find ideas and you can benefit from the research other students have done by looking at references in a paper close to your topic to see if they found any you did not.
You might find yourself with an incomplete citation and you really want that article. Use these tools to find the full name of the journal from the abbreviation in the citation.