Perhaps you should try some spelling variations:
associate director » associated vector
associated vectors » associated vector, associated factors, associated receptors
associate factor » associated factors, associated vector, 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 director) OR (associated vectors))) OR (associate factor)).
• Adding a wildcard symbol may retrieve word variants: ((((associate director) or (associated vectors))) or (associate factor))*.