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

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