Be as specific as you can. Use Boolean OR to widen your search. Use AND to narrow it. Don't use words too general or too common. Don't use plural forms, always singular 6.
Most searchers have an anvanced function.
You can use it to further narrow your search. Remember where you've been. Write it down in a notebook alphabetically. If you don't know what to use for key words, check an encyclopedia for ideas. Start with a wide search, then begin to narrow it if you get too much.