Perhaps you should try some spelling variations:
associated receptors » associated secretory, associated vector, activated receptors
associated factors » associated bacteria
associate director » associated vector
associate editor » associate editors, associate factor, associated vector

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 (((associated receptors) OR (associated factors))))) OR (associate director)).
• Adding a wildcard symbol may retrieve word variants: ((((associate editor) or (((associated receptors) or (associated factors))))) or (associate director))*.