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