Perhaps you should try some spelling variations:
associated factors » associated bacteria
associated vector » associated secretory, associated infection, associated operators
associate factor » associate editors, associated fatty

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((((((associated vector) OR (associated factors))) OR (associate director))) OR (associate factor)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((((associated vector) OR (associated factors))) or (associate director))) or (associate factor))".
• Adding a wildcard symbol may retrieve word variants: ((((((associated vector) OR (associated factors))) or (associate director))) or (associate factor))*.