The search options are two-part searches. Search once to locate the files that contain the character string of interest.
Go to the file of interest, and search again for the character string to find the exact entry.
Keep it simple! Searches must match the web text exactly, so long searches are unlikely to give good results.
No plurals. Search for "France map" not "French maps"
"And" not "Or". Use "and" whenever possible and only use "or" when "and" does not give the results you want. Searching for "Mississippi River Map" with "Or" will give thousands of results because of "river" and "map".
Start broad, then narrow your search as needed. Search for "Burlington", then "Burlington and Vermont" if you get too many results.