Perhaps you should try some spelling variations:
associated infection » associated infections
associated vector » associated factors, associated secretory, associated operators
associate editor » associate editors, associated factor, associated motor
associate factor » associated factors, 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: ((associate editor) OR (((((associate factor) OR (associated vector))) OR (((associated infection) OR (associate director)))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((associate editor) or (((((associate factor) OR (associated vector))) or (((associated infection) or (associate director))))))".
• Adding a wildcard symbol may retrieve word variants: ((associate editor) or (((((associate factor) OR (associated vector))) or (((associated infection) or (associate director))))))*.