If you are finding too much or not enough information, use keywords that are narrower, broader, or similar to the keywords you've already used to vary your results. You could also use boolean operators and/or truncation symbols.
You can combine keywords, boolean operators, and truncation symbols in a search to create a search string to retrieve the most relevant search results
Example: (Jelly OR Jam) AND peanut butter =/= Jelly OR (Jam AND peanut butter).
Example: "bed bugs" will not find "bed bug". Instead search for bed AND bug*, without the quotes, to get both variations.