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

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